leetcode1015

 class Solution(object):
     def smallestRepunitDivByK(self, K: int) -> int:
         if K % 2 == 0 or K % 5 == 0:
             return -1
         r = 0
         for N in range(1, K + 1):
             r = (r * 10 + 1) % K
             if r == 0:
                 return N