# -*- coding:utf-8 -*-
#2020秋招vivo算法题二题源

class Solution:
    def LastRemaining_Solution(self, n, m):
        if n < 1:
            return -1
        arr=list(range(n))
        r=-1
        l=0
        while arr:
            k=(l+m-1)%n
            r=arr[k]
            arr.pop(k)
            n-=1
            l=k
        return r