【AtCoder Grand Contest 010 D】Decrementing
【洛谷P6071】[MdOI2020]Treequery
【AtCoder Grand Contest 009 E】Eternal Average
【AtCoder Grand Contest 009 D】Uninity
【AtCoder Grand Contest 009 C】Division into Two
【AtCoder Grand Contest 008 E】Next or Nextnext
【AtCoder Grand Contest 008 D】K-th K
【AtCoder Grand Contest 007 E】Shik and Travel
【AtCoder Grand Contest 007 D】Shik and Game
【Ynoi2018】GOSICK