【AtCoder Regular Contest 058 E】Iroha and Haiku
【AtCoder Grand Contest 017 F】Zigzag
【AtCoder Grand Contest 016 F】Games on DAG
【AtCoder Grand Contest 020 F】Arcs on a Circle
【Codeforces 582E】Boolean Function
【AtCoder Grand Contest 020 E】Encoding Subsets
【洛谷P5616】[MtOI2019]恶魔之树
【洛谷P4950】完美数字