Our chemical biologists have invented a new very useful form of life called stripies (in fact, they were first called in Russian - polosatiki, but the scientist...
the i-th necklace has a brightness ai, where all the ai are pairwise distinct (i.e. all ai are different), the i-th bracelet has a brightness bi, where all the...
It is Professor R’s last class of his teaching career. Every time Professor R taught a class, he gave a special problem for the students to solve. You being his...
Emuskald is a well-known illusionist. One of his trademark tricks involves a set of magical boxes. The essence of the trick is in packing the boxes inside other...
Dima got into number sequences. Now he's got sequence a1, a2, ..., an, consisting of n positive integers. Also, Dima has got a function f(x), which can be defin...
It is my great honour to introduce myself to you here. My name is Aloysius Benjy Cobweb Dartagnan Egbert Felix Gaspar Humbert Ignatius Jayden Kasper Leroy Maxim...
The hot summer came so quickly that Xiaoming and Xiaohong decided to buy a big and sweet watermelon. But they are two very strange people. They are even-numbere...
