A - Gregor and Cryptography
Gregor is learning about RSA cryptography, and although he doesn't understand how RSA works, he is now fascinated with prime numbers and factoring them.
Gregor's favori...
A - PizzaForces
PizzaForces is Petya's favorite pizzeria. PizzaForces makes and sells pizzas of three sizes: small pizzas consist of slices, medium ones consist of slices, and large pizzas consi...
A - Subsequence Permutation
A string of length , consisting of lowercase letters of the English alphabet, is given.
You must choose some number between and . Then, you select characters of an...
B1 - Wonderful Coloring - 1
This is a simplified version of the problem B2. Perhaps you should read the problem B2 before you start solving B1.
Paul and Mary have a favorite string which consists...
