【Codeforces 1004F】Sonya and Bitwise OR
【PA2019】Trzy Kule
【Codeforces 767E】Change-free
【Codeforces 763E】Timofey and our friends animals
【Codeforces 763D】Timofey and a flat tree
【Codeforces 730F】Ber Patio
【Codeforces 735E】Ostap and Tree
【Codeforces 1292E】Rin and The Unknown Flower
【Codeforces 671C】Ultimate Weirdness of an Array
【AtCoder Regular Contest 087 F】Squirrel Migration
