Boning Dai: IMO 2024 Report

Because of the limitations of the NZMO website, this report has been shortened to include 10 images only. You can read the full version of it below: https://docs.google.com/document/d/e/2PACX-1vRcNtnZYq6CsUsWiZyIWb6AiHki0bjRTj7QafatNnlFDQBVWd6YRt8CipagYtt7r36Wj5HLqYaWbuf2/pub

Day 1:

I leave from Houston to fly to Heathrow, London. The issue of whether I should use my Chinese or New Zealand passport is quite confusing: however, since I am writing this report right now and not arrested for passport fraud, it can be seen that the issue has already been resolved.

Josie picks me up at the airport. I am eternally grateful to her for doing this, and we wait for a bus (which is late) that goes to Gatwick. The rest of the team is there, waiting in a Pret a Manger, a convenience store which sells quite high quality food. We have a meal there before departing on a 4 hour bus ride to Bath. Haotian and Jay play 2 Player Games, an app which will consume much of their time over the coming days, while Chris’s head wobbles worryingly as he sleeps.

We arrive at 11pm. It is raining, which is always to be expected in Britain.

Day 2:

I sleep well, and wake up to sit the first of four IMO shortlist mocks, which will be our only practice before the real IMO. We are sitting the mocks out of order, so this is actually Mock 2: the Netherlands team, with whom we are training, have already finished Mock 1.

The questions are questions (G2, C2, A5).

Problem 1 is geometry, which I solve by noticing that one of the points is a circumcentre.

Problem 2 is apparently an algebra-flavoured combinatorics, which leads me astray. I struggle with the problem for several hours, finding the construction along the way but failing to do anything of value. Finally, in the last hour, I realise that the sum of subsequences can be bounded similarly to 2014 A3. However, the bound I use is a little too good, and I do not get enough information about the terms in the rest of the sequence to solve the problem.

I remember nothing about Problem 3.

After the exam, Haotian tells me that the solution is to use a greedy algorithm, which gets a slightly worse bound but retains a lot more information about the sequence. Coincidentally, that is the other way to bound the sequence in 2014 A3.

In the afternoon, we mark the mocks. I get 7/1/0, losing a mark on Problem 2 for writing up the proof of the construction badly. Ross reveals an incredible solution to Problem 3, involving elevators and a basement.

Day 3:

We visit the Roman Baths, which the town is famous for. It is also famous for its Bath Buns. Two shops, the Sally Lunn and The Bath Bun, hold a duopoly over the town’s supply. Before the trip, I googled a list of interesting things to do in Bath: third ranked on that list is judging the “Battle of the Buns” between the two shops, which speaks to the number of things to do in Bath. Sadly, we will consume exactly zero Bath Buns over the course of the trip.

The Roman Baths are nice, with lots of historical facts about the Romans. Jay tries to get me to fall into the bath, but he is unsuccessful. Dawn is particularly interested in the lead tablets used for cursing others, which is why I am extra nice to her for the rest of the trip. Before leaving, we are invited to consume the mineral water from the baths. It tastes like eggs and rust.

I buy a wooden dagger at the gift shop. Before leaving, we visit the best fudge shop in Bath, which tries to tempt us with a student discount.

After visiting the town, we go on a Bath skyline walking tour with the Netherlands team. It is long and tiring. Cows are seen. We play frisbee in a field somewhere along the way.

Finally I have time to go to the grocery store inside the campus and buy shampoo, which I forgot to bring on the trip. The walk makes everybody sufficiently tired that we all decide to sleep early to prepare for the mock tomorrow.

Day 4:

It is time for Day 2 of the mocks, which is actually Mock 3.

The questions continue to be questions (N3, A4, C6).

Problem 1 is a number theory which is solved by Legendre’s.

Problem 2 is a functional inequality, which seem to be rising in popularity recently. It is a sad fact of life that real to real functional equations are dying out. Now the new fad is positive reals to positive reals, which prevents me from substituting in zero.

The question is scary. I substitute in a few numbers to get a feel for it, then fool around with it for a few hours. I realise that I am meant to prove f(f(x))=x. f(f(x))≤x is easy to prove, but the other direction is harder. Finally, I look back on my work and find that I can get a contradiction if f(f(x))-x is greater than zero since the gap between f^(2n)(x) and f^(2n+2)(x) is nondecreasing.

Problem 3 is grid combinatorics. I make no progress on it, but Bas from the Netherlands team solves it by cutting the grid and piecing it back together so he can induct downwards.

Again, we mark the mocks. My writeups are sufficient for 7/7/0.

Day 5:

It is time for Day 3 of the mocks, which is actually Mock 1.

The questions are questionable (A1, G3, N7).

Problem 1 is an algebra problem disguised as combinatorics. While some of my teammates find a combinatorial solution, I instead quickly prove that the greedy algorithm gets the desired bound through the probabilistic method.

This means that I have lots of time to dedicate to Problem 2, my nemesis of Geometry. I manage to characterise point P early on, and conjecture that a homothety is required, but I do not make the crucial observation of flipping the orientation of the triangle, so I don’t solve the problem.

Problem 3 is number theory. I read it somewhere around the 3 hour mark, then go back to staring at my diagram for Problem 2.

Nico manages to complex bash Problem 2, while Haotian finds a nice trig bash. Synthetic geometry is dead, and we have killed it.

We mark the mocks. My characterisation of P gets me 2 marks, but I lose 1 mark on Problem 1 for not proving a simple lemma which I use in the probabilistic method solution, meaning that my score is 6/2/0.

Day 6:

During breakfast, I arrange my muffin crumbs into the vague shape of a number (19) like a fortune teller to try and predict bronze cutoffs. Fortunately, my estimate will turn out to be inaccurate.

But enough of that; now it is time for Day 4 of the mocks, which is actually Mock 4.

The questions are (C1, N5, G7).

Problem 1 is a combinatorics problem. I struggle with it for 2 hours before locking in and noticing that a colouring which I wrote down 4 pages of rough working ago works.

Problem 2 is number theory. I get stuck in analysing the v_p of the sequence and make zero progress because I didn’t define the helper sequence which is necessary to solve the problem.

I draw two circles for Problem 3, then give up on it.

After the exam, I realise my conjecture for the answer to Problem 1 is actually wrong; while I thought the answer was (m, n) for which 6|mn, the answer is actually 3|mn. While my proof is technically a superset of what is required for the question, I lose 2 marks since I didn’t construct a usable covering for some of the grids. I score 5/0/0.

Day 7:

Arrival day can be thought of as the first real day of the IMO, when most of the other countries who are not lucky enough to have a training camp arrive and greet their rivals/friends (mostly friends, unless you can’t socialise like some people on this team). We go to collect our new room keys and a set of IMO-branded merch, which is very cool, and probably would sell on eBay for a nonzero amount of money.

Our new rooms are exactly the same as our old ones, except for the fact that the drains are absolute garbage. When I try to shower later that day, I will have to stand on the cold bathroom floor, staring at the drain, for a minute before the water completely disappears and I can resume my shower again.

We play sports in the gym. Dawn demonstrates her badminton skills, while I am beaten at ping-pong by first Haotian, then Nico, who takes the opportunity to practice his spin shots. Later, Chris, Haotian, and I have a free throw competition, during which we realise none of us possess the spirit of Kobe.

The XTX hub is now open. There is a popcorn machine, along with free drinks and snacks. I try to play the piano there, but none of the notes sound right. Is it out of tune? Am I just bad? The question is up for debate.

Also in the XTX hub, I also meet POR6, who is famous on the Mathematical Olympiads Discord Server for being sad a lot and also talking a lot. I cannot decide whether it is better or worse to meet him in person.

Bath is gray and moody on most days, but today, the weather is uncharacteristically good. Shamefully, I hang out with my team in the hub instead of going outside to enjoy the weather.

Football fans will note that today is the day of the Eurocup finals, which is Spain vs. England. Many people are watching the finals as we prepare for quiz night, which turns out to be a 2-hour slog through obscure trivia. We come second place to Team Soccer, who probably would have had more fun if they went to watch the Eurocup instead.

Before going back to sleep, I receive the news that England has not won the Eurocup. Congratulations to Spain for upholding the game of football against the tide of English football hooligans for one more year. Now mildly optimistic, I go to sleep after spending some time with Chris and Jay.

Day 8:

Opening day is the actual first real day of the IMO, when all the countries parade on stage and their students try to not look too stupid in the photos. Sadly, I fail at this.

Before the opening ceremony, we attend a talk by Daniel Tammet, whose claim to fame is his number-based synesthesia. Most of the content is vaguely familiar. I’m pretty sure that I’ve read a book by him before, so I try not to fall asleep as he talks about his experience of memorising pi and his childhood living with autism. Fortunately, there is one good thing to come out of the wasted hour: we receive a free, signed, copy of his book.

(I am told that Simon Singh, 2 days later during his talk, casts shade on Daniel Tammet by pointing out the unverifiable nature of his synesthesia.)

POR6 is right across the aisle from us during the opening ceremony. I wave to him again. He seems confused. Maybe he is simply nervous, crushed by the expectations that he has for himself of winning a bronze medal, which he will fail to fulfill over the course of the next two days, but for now the exam is still 20 hours away and life is good.

Many people give speeches, and then the countries start walking across the stage and showing off their flags. Team China, a team of six William Fans (because of their mathematical ingenuity), drops their flag multiple times before finally succeeding in sharing it among themselves. That is a crime punishable by up to a year of imprisonment in America. Fortunately, Team USA holds their flag normally.

When the leaders wave to their teams from far away after the ceremony is over, Ross is absent for some reason.

We hang out in the XTX hub again and meet Jessica Wang, the official volunteer photographer for the IMO. Dawn and I talk to her for a bit while playing a Carrom-like game (she wins most of the rounds), and she tells us that she came over from Germany by train to help and take some time off from her maths PhD. I am amazed at the small size of Europe. She also shows us the Facebook account that she is using to post the photos, which surprisingly few people know about.

The Day 1 exam is tomorrow. Chris, Jay, and I go with Kevin to buy snacks for the exam; Jay gets way too much, while I opt for white chocolate and Jaffa cakes, both classic British delicacies. On the way back, we decide to visit the chaplain, who kindly listens to our situation and offers a prayer for academic success. In its wake, I feel slightly more confident.

I sleep early tonight, but not before having an epiphany, which I tell to Chris before promptly forgetting the next morning.

Day 9:

I wake up at 6:40, having slept well the night prior, in preparation for an 8:00 start to the exam. A large amount of light behind my curtains makes me think that it is bright outside, but it is the result of a streetlight, which was on the entire night.

We enter the exam hall at 8:00, and are forced to sit there for half an hour before being allowed to begin. The sealed envelope containing the problems taunts me as I watch the clock nervously, and when the exam starts, I rip open the envelope only to discover what looks like three number theory questions.

Fortunately, the distribution is A1, N4, C7 instead of N, N, N. Perhaps unfortunately, all three problems involve sequences.

Problem 1 is an algebra involving floors mod n. I figure out the general gist of the solution through doing the decimal part substitution, but it takes me another hour to write up the solution because I discover several pitfalls along the way. In the end, I am still unhappy with the solution, but I have three hours left for Problem 2, so I move onto that.

Problem 2 is a number theory problem involving powers and gcds. I try to find a prime p that divides both initially, but it requires p|a+b, which is too narrow of a relation to work out. As a result, I switch to trying to find p|a^n+b, then making the relation work for b^n+a later. Fortunately, I notice that the relationship is symmetrical since a^n=-b mod p and b^n=-a mod p, so a^(n+1)=b^(n+1)=-ab mod p. I know by Fermat’s that I can find lots of values of n such that a^(n+1)=b^(n+1)=1 mod p, which motivates me to try and find p such that -ab=1 mod p, which reduces to p|ab+1. From there, it is only a matter of finishing off the problem, and I look over my solution twice before being content that it is correct.

Problem 3 is a combinatorics problem involving a strangely-defined sequence. I try some small cases, then decide to give up and shore up my solution for Problem 1 instead of trying to chase partials on it. I end up having to do a full rewrite of my Problem 1 solution, which is much clearer, and I prove that infinitely many 1’s occur in the sequence in the last half hour, which is nowhere near enough for a mark.

Exiting the exam hall, I am surprised to hear that nobody else solved Problem 2. Dawn realises that she was close to a solution, but will probably be getting partials instead. During lunch, I think a bit about my solution and suddenly realise that I might have missed a case in my writeup, but decide not to worry about it since Ross will get me all the marks he can.

To take our minds off the exam, we go out to mini golf with the Netherlands team, then play some tennis afterwards. On the way back, I take a few pictures of birds, beginning an obsession with the avian occupants of England that spirals close to insanity in the coming days.

Day 10:

My sleep is similarly undisturbed. Again, I sit in silence for 30 minutes before the start of the exam, ready to tackle the problems, which I predicted as C, G, A before the exam.

My logic was that Problem 3 was combinatorics, so the Problem Selection Committee would put an easy combinatorics on Day 2 to balance it out. Similarly, no problem on Day 1 was geometry, and having the only geometry question be a Problem 4 would be unfair to those who specialised in geometry, so geometry would be Problem 5 and I would (hopefully) solve p4 quickly, then try and scrape a few partials from the geometry.

Shockingly, when I open the exam, the distribution is instead G2, C4, A7. I imagine the anguished screams of hundreds of EGMO readers throughout the exam hall, but am happy to have a geometry Problem 4, which gives me a chance to solve Problem 5.

Problem 4 is a geometry problem involving midpoints, tangents to an incircle, and a really weird angle condition which I have to prove sums to 180. The diagram is hard to grapple with. Initially, I try dropping perpendiculars from the circumcentre, which nicely deals with the midpoint and incentre condition, but after an hour of angle chasing, I have gotten nowhere. Then I spot the homothety and parallelogram created by extending the tangents, then try to reinterpret the problem somehow to get a cyclic quadrilateral for the angles that sum to 180 by angle chasing, which is similarly confusing. I look up around the 2 hour mark and realise that the exam is almost halfway over. Despair sets in. My last resort is a prayer to god to apologise for my hubris in thinking I could solve 2 problems, which I mutter in my head while staring at the ceiling. 5 minutes after the prayer, I spot the cyclic quadrilaterals and solve the problem.

Problem 5 is a combinatorial game on a grid between Turbo the Snail and the monsters which seek to block him from reaching the other side. I try my small cases, and, seeing a linear increase, conclude that the answer must be 2023, then get stuck on this for the rest of the exam. Somewhere in the middle, I realise that the first-row monster must be on the edge, otherwise Turbo can win by going around it, but never bother taking this further. Instead, I try to colour squares Turbo knows are safe, which gets nowhere, then throw my head against small cases again to try and gain more insight. I also realise that Turbo wants to get above a monster since he knows that column is safe, but the lack of information about the other monsters makes that difficult without incurring more tries. Therefore, I try to prove that Turbo must hit each monster exactly once to win, which is hard precisely because it is impossible to prove, and fail the problem.

Problem 6 is a functional equation. I would like it more if I had had more time to try it, but instead I just prove that f(0)=0 after 5 minutes of subbing in values and go back to Problem 5.

After the exam, I talk to Ellen from South Africa behind me. She tells me the solution to Problem 5, and I think about it for a while before realising that it is not only 100% correct but also much easier than I imagined. Indeed, Chris, Jay, and Nico have all solved the problem. I feel sad, but hope for partials.

We attend a Matt Parker lecture later that evening. He talks for a while about the versatility of Python, specifically in programming his Christmas tree to flash in a really cool way, and also about some problems he has been working on, such as non-unique ways of folding a net and the search for five Wordle words which contain 25 different letters among them. Throughout the lecture, it is a common theme that his viewers code better than he can, improving his algorithms while ridiculing him at the same time.

The lecture is not long, but that is because of the talent show Matt Parker is also hosting. I am doubtful of the talents IMO participants may possess apart from maths, and the acts that night do not prove me wrong.

The Japanese team guide karaokes Six Trillion Years and Overnight Story. He is actually quite good at it: the enunciation is clear, even if his vocal range is a bit lacking.

The Finnish team, along with some other Nordic teams, demonstrate a classic circle dance, which is meant to make fun of the English and French. At first they are a bit confused about which way to rotate, but eventually they get the hang of it and frolic on stage for a few minutes before leaving to rapturous applause.

A Balkan team raps in their own language. Some of the words sound a little rude in English, but they are on beat.

During an interlude, Ben Sparks shows off a way flowers pack their seeds efficiently and proceeds to sing a song about it. There are a lot of songs in this talent show.

Somebody, flanked by three providers of moral support, performs a magic trick on Matt Parker. No comment.

Clementine, a team guide next to us, demonstrates her love for opera by hitting every note in “Mon cœur s'ouvre à ta voix”, from Samson and Delilah. Dawn is also dragged on stage for her proficiency in French. The singing is very good, but because Clementine is a guide instead of a competitor, my hypothesis about the talents of IMO participants still stands.

Later that night, we play Mao with some people from the MODS Discord server. They are nice people, and we leave vowing to play together again (we never did). We stay up until 2am, and then I go back to my room to look at the internet until 4am, thus beginning a terrible cycle of bad sleep schedules which will haunt me for the rest of the IMO.

Day 11:

We wake up early again for an excursion to London, meaning that I get approximately 3 hours of sleep. I make up for this with a cappuccino, diluted with milk. Since I rarely drink coffee, this is an effective stimulant and leaves me feeling like I am about to have a heart attack. We first ride a train to Paddington station (which does contain the famous Paddington bear), then take another train through the London underground to the Tower of London. I sleep on the way and dream about a cup of water dropping. As I reach out to catch it, I flail my hand, knocking my seatmate’s card holder off his table, and wake up to realise what I have done.

After viewing a mural about the history of London, we take a look at the Tower, which, according to our tour guide, was built by William the Conqueror to fortify both his power and the city. A section of Roman wall still stands next to it, and the Tower itself is less of a tower and more of a castle. Afterwards, we visit a nice gift shop. I resist the urge to buy a wooden sword and instead just get souvenirs for my family.

The Tower is also close to Tower Bridge, which was famously destroyed in the 2021 hit film Spiderman: No Way Home. Fortunately it seems to have been rebuilt, and we walk across it nervously after hearing a story about a bus which nearly fell off the bridge while it was opening up to let a boat through. On the other side of the river, we can see the gleaming glass buildings of London’s financial sector. In the river itself, two birds are fighting. One loses and flies away.

We arrive at Leadenhall Market, famously the site of filming for part of Harry Potter, just in time for lunch. Instead of buying food at the market, we opt for guide-sponsored food from another nearby Pret a Manger. Luckily, we have some time to explore. I buy a pretzel as big as my head and am tempted by a bottle of truffle vinegar, which I decide to be far too expensive in the end.

In the afternoon, we visit Big Ben, which looks very golden and shiny against the blue sky. Westminster Abbey is nearby, and we visit it as well.

Something more interesting is St. James Park, which is right next to Buckingham Palace and contains a wide variety of birds. I dutifully document every one. Sadly, we are unable to tour Buckingham Palace, but we do get a group photo outside of it, which looks worse than expected because of the large crowds gathered right in front of the gates.

Later that night there is a lecture from Grant Sanderson, better known as 3Blue1Brown, about reinterpreting 2 dimensional problems in terms of 3 dimensions. After the lecture, I trade souvenirs with the Japanese team and receive a very nice keychain.

Day 12:

Originally, we were meant to go on an excursion to Bletchley Park today, as recommended by Josie. Unfortunately the trip was too popular, so we were allocated to Stonehenge instead. Rather than sitting in a bus for several hours just to look at something we could build an approximation of in the XTX hub, we decide to go on an excursion of our own to Bristol instead.

Climate change is out in full force, as can be seen by the high temperature there. Dawn offers the group sunscreen. After New Zealand sun, English sun is nothing; therefore I refuse, using the excuse that my skin is naturally reflective. She almost believes it. We walk around Bristol, eventually finding a mall by the river, containing a science museum and a very cool disco ball, touted as the world’s first 360 degree planetarium.

Haotian is so busy looking at the disco ball that he squishes a snail. It is Turbo the Snail. Turbo is dead now. Hopefully this was part of his strategy and he will make it to the other side on his next attempt, but looking down at the snail, all I can feel is a sense of schadenfreude. Perhaps we were the real monsters all along.

Eventually we arrive at the waterfront and follow it until we reach a wharf. There is a boat housing a photography competition there, as well as a nice painting. I would have taken photos of the photos, but they were so good I became insecure of my own skills. The dock wobbles worryingly as we step on it, and the entire group promptly synchronises their strides to create simple harmonic motion.

Josie tells us about a suspension bridge which is said to be quite famous. It is a long walk to the suspension bridge, the only saving grace of which is Josie’s promise that lunch will come as soon as we get there and down again. There are said to be Banksy murals in Bristol, but we only see graffiti. The bridge is on top of a hill, which is not good for our legs as we first trudge through a forest, then realise that there is a highway right next to it and walk on that instead. A small information centre is there. Haotian, aged 16, designs a bridge and enters it into the bridge-drawing competition. In my opinion, Ben, aged 7, did a better job. The view from the top is nice, but slightly foggy.

We have lunch at a restaurant, the name of which I cannot remember. There is free wifi there. Wendy from the Netherlands tells us that partial results are out, and I am relieved to see that Problem 2, which I thought I would lose marks on, has gotten a 7 through the magical machinations of Ross and Kevin. Jay is surprised at his 2 partial marks on Problem 2. I am less happy at my 1 for Problem 5, but any mark is something to be proud of, as Ross says. I get a lamb skewer, which honestly was not worth the price. The taste of the lamb is overshadowed by many of the sides, which included pickled vegetables, three dipping sauces (one of which is quite spicy), and a flatbread so tough I have to tear it with my teeth.

After lunch, we finally have a chance to look around the city proper. There are two Banksies, one of which is defaced, but the other one is still fine. At this time, school is ending in Britain, so there are many university graduates wandering the streets in search of a job, wearing their caps and robes.

The train ride back is short. Once we arrive, we see the famous Evan Chen, author of EGMO, at dinner. I am ashamed to not have brought my digitally pirated copy for him to sign. Somehow, another New Zealand sticker finds its way onto his back.

Later that night, Jay, Chris, and I speculate on medal cutoffs, against Ross’s advice. Chris and I are on 22, while Jay is on 23. Medal cutoffs are either 22, 23, or 24. The discussion is fruitless as we are lacking information apart from the results website, which has some censored scores. I count every person with score ≥ 22 and find no useful information.

Jay writes up a simulation, which works by taking the censored scores and replacing them with a random score from another person on their team for that problem, and predicts that cutoffs will be 17/23/29. In fact, he is so confident about this that he not only sets it as his Discord status but also his Instagram note.

I am also confident about this result, but in a sad way, and spend the rest of the night being sad with Chris until 4am.

Day 13:

There is nothing to do today, so I sleep in until 10, then sleep in for a bit more, then scroll MODS on my phone. On the server, the Portugal team leader says that cutoffs are 16/22/29. Hooray! I miss breakfast, of course, but that is easily replaced with the snacks from the XTX hub.

The next lecture comes from Thang Luong, one of the creators of AlphaGeometry, a testament to the weakness of flesh. Synthetic geometry is dead, but now, it is the robots who have killed it.

(Note: at the time of writing, I have been made aware that AI has successfully solved 4 problems of the 2024 IMO, receiving a score distribution of 7/7/0 7/0/7, 1 point off from a gold medal. On a completely unrelated note, I will be switching to Ethics Olympiad next year so that I can run from our AI overlords for a while longer.)

In the evening we go for another walk about Bath, this time a normal walking tour. We learn about fake windows, tall Georgian hair, whiskey used to preserve the body of a famous person, and things that I have probably forgotten which weren’t that interesting anyways. By the time we get back, it is raining. There is a fat pigeon sheltering from the rain in a street corner.

We arrive just in time for dinner. Tonight holds a lecture from Terence Tao about Lean, which is an AI tool that real mathematicians use for doing real maths. The room is too full to accommodate us, since we are late. Faced with the prospect of watching the lecture on an overhead screen in the adjacent room, I skip out on both dinner and the lecture to hang out in the XTX hub and eat their free snacks instead. British food is too terrible for any person to consistently consume.

I’m pretty sure we also played Mao again tonight, with the rest of our team, Ross, Josie, Kevin, Ishan, and Alice, who is part of the Problem Selection Committee. Eventually the rule interactions get so confusing that we simply give up.

After the game of Mao, Chris, Dawn, Tobias (NLD4), and I walk around the campus. While the XTX hub is closed, there are still people outside it using the outdoor activities. Chris and I play shuffleboard for a while before we are pulled into a game of mafia with a Balkan team which I have forgotten the name of.

The game of mafia goes well, but there is no interest for a repeat, so we decide to go and explore the rest of campus. There are many slugs and snails out at this hour, Turbo’s brethren heading for destinations unknown. We walk for a while, then decide to go to the lake. On the way, we spot a party composed of the South America teams. Suspiciously, alcohol is involved. Eventually we end up at a small table there before deciding to head back to our dorms.

Day 14:

Today is the day of the closing ceremony. Without any pressing events to attend, I sleep in again until 10.

I am too late to eat breakfast, but I make up for this with food from the XTX hub again, and stay there until it is time to leave for the ceremony.

I go up with Chris to receive my silver medal. It is a bit disheartening to realise that my silver medal is the result of country leaders being generous with cutoffs, but as Ross says, medals depend on how well everybody else did anyways, so they don’t really matter. I have an awkward conversation with somebody, the details of which I have erased from my memory.

After the ceremony there is an afterparty. Somehow IMO has gotten the funding for a carnival with free food trucks, rides, and games. I make a spirited attempt at eating something from every truck, but only manage to get through the grilled cheese, pie, fish and chips, ice cream, ice cream roll, churro, pizza, and pizza trucks. Luckily I do not throw up on any of the rides, including the bumper cars, during which I brutalise SAF1’s (Moied’s) car. Before the closing of the fairgrounds, there is a fireworks display.

As is tradition, we stay up late. The semantics are debatable, since I have been going to bed after 3am consistently in the past two nights, but the sentiment is there. Most of the Netherlands team and the New Zealand team heads off to sleep after a while. Ross leaves for the airport at 1:30am, and Chris, Dawn, and I are there to say goodbye to him.

Day 15:

Today is the day we leave for the Jane Street Maths Olympiad Celebration. All the teams sponsored by Jane Street were invited, which does mean that some others were left out. All in all, there are probably about 150 people at the event.

We sit on a bus for 3 hours. Jay is grumpy the whole way because his lunch fell out. In fact, he is grumpy for almost the entire event, the reason for which is unclear. To be fair, being on a bus for 3 hours would make anyone grumpy. Haotian and Nico play 2 Player Games before Haotian finds a “buddy” (his words) from the German team.

The hotel (Hyatt Place) is luxurious after two weeks of uni accommodations. I am able to relax for a while before heading to the rooftop for Jane Street food (not as good as the XTX hub food, even if it is fresher) and a game of Jane Street branded Hanabi with the Croatian team. We manage to get pretty close to victory on the first round, but the second round goes badly, and I leave to prepare for the excursion later that night.

The excursion is to the Science Museum. But we do not explore the museum; instead we are locked up in the basement, in the history of gaming exhibit, to play games and eat fancy catering, which is a bit like casting pearls before swine (or playing the lute for a cow). The computer with Minecraft is already occupied, so I wander around until the event is over.

The menu:
vegetable tart that tastes like foie gras
raw tuna taco
Korean beef cube with yellow sauce
vegetable spring rolls
mushroom balls with tomato paste and leaves
carrot cucumber radish salad with leaves
lobster paste and cheese and bread
mac and cheese with spicy chicken
chocolate coins and biscuit
tiramisu

Pizza is provided when we return to the hotel. There is nothing else to do, so I hang out with Chris and Jay for a bit before taking a very nice shower and going to sleep.

Day 16:

I sleep in and am woken up by a knocking at my door. After dressing in a record time of two minutes, I rush to the downstairs lobby and find that not everyone has departed for the Jane Street offices yet, which is a happy surprise.

Jane Street does not allow photos in their office, presumably to prevent secrets of their top-secret trading algorithms from leaking. Their breakfast is nice. In fact, all of their benefits are nice. When you want your employees to stay in the office for longer, the optimal strategy is obviously to make them want to stay in the office. If an employee was determined enough, they could probably even sleep in the office.

After breakfast, there is a lecture on cognitive biases. I manage to keep my eyes open, but Dawn is not so lucky. Following the lecture is a chip trading game; I manage to do well on the first round, but on the second round the Serbians in the row behind us form a coalition to drive down the price of black chips. I do not sell my black chips to them out of pride.

The schedule then guides us to the River Thames, where Jane Street has prepared an entire boat for us as well as British afternoon tea. Unlike last year, when we didn’t eat any sushi even though we were in Japan, this year we are lucky enough to be able to try the local food.

Most of my attention is occupied on the board games provided, although I do go up to the top of the boat near the end. Haotian is there with his buddy. A dead bird lies on one of the windows. As I have been doing for the entire trip, I dutifully photograph it.

After the cruise, we return to the Jane Street offices for a lecture from Matt Parker. It is slightly more interesting than the lecture about cognitive biases, but of more interest to me is the dinner after the lecture. I am unable to take photos, but the food is pretty good, you gotta trust me on this, Jane Street is the best company to work at for everyone because of their great employee benefits and generous compensation packages.

Apart from the dinner, there are many activities there. String art is provided for those with time to spare, and there are puzzles as usual, as well as decks of cards and poker chips. I end up playing cards and not eating much food in the end, since I already had afternoon tea.

The merch is not as good as last year, being composed of a plastic tote bag, a t-shirt emblazoned with their logo, a deck of cards, and a single sticker. It is free though, so no complaints. I take a balloon from their dinner, but while I am attempting to consolidate the merch I accidentally fumble and it flies up to their ceiling.

Jay, Chris, Dawn and I decide to stay up. The German team joins us for a game of Codewords. My sleep deprivation over the past few days has gotten to me, and I do not remember anything that happens apart from taking a selfie to send to my mom when she asks me what I’m doing at 2am.

Day 17:

It is the hour of departure. I sleep in for the second day in a row. Fortunately, someone else is later than me. Josie accompanies me to the airport, which I am again very grateful for.

The plane ride back is uneventful, apart from the hazmat containers stored close to me. I have a window seat, which I take full advantage of.

Questions:

Before I answer the questions, a word from today’s sponsor:

This report is sponsored by Jane Street, one of the biggest quantitative trading companies in the world! Currently almost 2600 employees have joined Jane Street, and it's one of the most prestigious companies in its industry with detailed models of the market, employee benefits, and 5 offices around the globe!! Your workday can be customised the way you want, with premium catered food, snacks around the office, and up to 15 days of PTO per year!!! The markets we work with are very interactive and figuring out the best algorithms to model them is a lot of fun!!!! Currently with over 500 reviews, Jane Street has almost a perfect score on Glassdoor!!!!! The company is growing fast and the highly anticipated neural network project is now complete!!!!!! You might even find our bots trading in the market! It's easier to start now than ever with a bonuses program for new employees; you get equity-based compensation for the first year in the company!!!!!!! So what are you waiting for? Go to our website, click on the link to apply, and you'll hear back from one of our hiring managers within 2 weeks to start your journey!!!!!!! Good luck and we’ll see you there!!!!!!!!

• How has attending this event demonstrated greater knowledge of available career paths in science and technology?

There was lots of discussion about potential career paths during the lectures and at the Jane Street event, and I have learnt a lot about the places that Olympiad maths can take you.

• How has attending this event enthused or inspired you to pursue science and technology careers?

I was already thinking about using my skills in STEM when I get a job, so there was no real change. The only difference is that I now know more about the companies I can work for, such as Jane Street or XTX.

• Has attending this event changed about how you feel about science or technology?

Before, I thought that the pursuit of understanding was a goal in and of itself; however, I have now realised that the application of science and technology in our daily lives is the true endgoal of the pursuit of knowledge.

• How has attending this event and participating with like-minded students been of benefit to you?

I got to meet lots of cool people, some of which I hope to keep in touch with in the future. Olympiad maths really is a tight-knit community.

• Now that you have had time to reflect about your experience, what have you learnt about yourself?

I have learnt that I should be more confident in my own abilities, but not overconfident. I have also learnt that I need to get better at maths.

• What did you enjoy about your experience?

Same as last year. I think this entire report answers this question sufficiently.

Conclusion:

It has been a pleasure to be part of the mathematical community in New Zealand for so long, not only because of the personal growth I have experienced but also because of the many friends I have made along the way. Of all the people who were with me on this journey, the few who were on this trip as well deserve special thanks.

Thank you to Ross, for always being a reliable team leader and putting in the effort to fight for every mark we deserve, even the marks that we deserve somewhat less, and also for always having clear, intuitive solutions to every problem we encounter. I enjoyed the problems you lectured about the most without fail.

Thank you to Josie, for your constant support on this trip. Without you, we would still be stuck in Bath right now, probably having lost our passports somewhere along the way. Again, and I cannot stress this enough, thank you for going out of your way to pick me up from Heathrow airport and sending me off there as well.

Thank you to Kevin, for helping Ross to fight for our marks, as well as just being a really cool person in general whom we had great conversations with. Having you alongside us for most of the trip was a great source of comfort because of your experience as a past IMO competitor.