【AtCoder Grand Contest 018 F】Two Trees
【AtCoder Grand Contest 018 E】Sightseeing Plan
【AtCoder Grand Contest 018 D】Tree and Hamilton Path
【AtCoder Grand Contest 017 F】Zigzag
【AtCoder Grand Contest 017 E】Jigsaw
【AtCoder Grand Contest 017 D】Game on Tree
【AtCoder Grand Contest 016 F】Games on DAG
【AtCoder Grand Contest 016 E】Poor Turkeys
【AtCoder Grand Contest 016 D】XOR Replace
【Codeforces 1303G】Sum of Prefix Sums