【Codeforces 735E】Ostap and Tree
【AtCoder Regular Contest 086 E】Smuggling Marbles
【Codeforces 512D】Fox And Travelling
【Codeforces 516D】Drazil and Morning Exercise
【Codeforces 868E】Policeman and a Tree
【Codeforces 461B】Appleman and Tree