# IMO 2015 Diary – Part Two

Saturday 4th July

The morning brings double embarrassment. My weekend alarm is still on UK time, so I arrive at the practice exam a) late; and b) to discover that I’d already set a question from today’s paper for one of our selection tests in May. Andrew and I scramble to find a suitable replacement in the knowledge that this day can only get better.

The end of the exam brings news from the UK, in the form of an article about Joe in the Guardian, featuring punditry from Geoff, and a cameo quotation from Warren, quashing some of the more ludicrous claims in another recent account, which, though entertaining, is about as reliable as the Sunday Sport. Neel spends much of the rest day standing in front of a blackboard staring slightly off to the left into a strategically-placed desk lamp, practising for when his own moment of fame, and accompanying photoshoot comes about.

The UK students have lived up to their star billing, producing some stylish solutions to an algebra question, and marking is pain-free. After a slightly questionable Indonesian meal, Jill and I try to find the fruit our team have requested as exam refreshments. The closest thing I can find to grapes are kedondong, and these turn out to be almost entirely unlike grapes, with a hard leathery outside covering a hard woody inside. Harvey is unimpressed.

Sunday 5th July

These exams are not supposed to be especially comfortable, but those among us who sampled the chilli and peanut sauce last night now have 4.5 painful hours to ponder the consequences of our decisions. Today’s scripts are also rather bloated, with a set of competent but vague combinatorics essays to wade through. If Wagner wrote mathematical arguments, they would be like this: impressive length, with occasional dramatic conclusions separated by long passages where nothing of any importance really happens.

Wanting a break from the eternal air conditioning, Sam, Lawrence and I head for a walk through the suitably steamy path leading up the hill through the jungle behind the school. It doesn’t really lead anywhere except a radio mast, so we soon find ourselves back in the diplomatic precinct. This poses a map-reading challenge since every street is called ‘Diplomatic Street’. Furthermore, one cannot rely on landmarks since, despite the Malaysian government’s prompts, only Iraq has actually got round to building an embassy here.

I am pleased to see that our students are eating the kedondong, if only as the bankruptcy forfeit for their endless poker game, which I’m also pleased to see has displaced some of the more inane traditional maths camp card games.

Monday 6th July

To mix things up, today the UK students have chosen an exam paper for the Australians, which they mark in the early afternoon, and vice versa. The point of this exercise is to force the students to learn first-hand what makes written work easy to understand, or otherwise. Warren and Lawrence have a number of subtle ‘case bashes’ to check, but Australians Jeremy and Seyoon have the short straw, with another set of UK essays, this time about moving dominos around. However, they’ve really engaged with what our students have and haven’t done, so when Andrew and I check that everything is in order, there are no major surprises. This leaves time for me to give a short talk on the Lovasz Local Lemma, which is fairly well-received, though everyone seems surprised that so much extra machinery gets you only an extra factor of $\sqrt{2}$ on the lower bound for Ramsey numbers.

As we have a bit more free time, Jill and I take the opportunity to visit Putrajaya’s two giant mosques. Jill’s efforts to dress appropriately ‘decently’ are in vain, as she is compelled to wear a giant burgundy hooded coverall for the duration. The stark ‘iron mosque’ includes a shopping arcade, and its main prayer room can fit 25,000 worshippers, who are I’m sure grateful for the air-conditioning hidden, our guide tells us, in the pillars. The Putra Mosque is just as pink on the inside, leaving Worcester College’s chapel green with envy.

Tuesday 7th July

It’s the final practise exam, deemed to be the Mathematical Ashes, which for the second time in three years finds itself well-timed in relation to its cricket counterpart. There is a both a trophy and an urn full of charred (mostly British) mathematics, which were only found hidden in a cupboard in Leeds last week, so they are not with us. Naturally, this has been interpreted as a sign of our confidence in retaining the title, and typical colonial arrogance.

It appears initially that no-one will be earning the title, as we are locked out of our usual classroom, and the alternative has plenty of sofas, but neither tables nor chairs. All is resolved quickly, and before too long, it’s time for another marathon bout of marking. About five hours later, Andrew and I have met to agree our marks and are able to make the dramatic announcement that this year we have a tie, on 84 points apiece. And no, we didn’t fiddle it. If nothing else, I’m definitely not good enough at addition to track these sorts of sums in my head.

And so the spoils, and the celebrations are shared. Our final Malaysian meal involves multi-coloured dim sum by the far side of Putrajaya Lake. Almost certainly the most greens some of the team have eaten all week…