Given a positive integer K, you need find the smallest positive
integer N such that N is divisible by K, and
N only contains the digit 1.
Return the length of N. If there is no such N, return
-1.
Example 1:
Input: 1 Output: 1 Explanation: The smallest answer is N = 1, which has length 1.
Example 2:
Input: 2 Output: -1 Explanation: There is no such positive integer N divisible by 2.
Example 3:
Input: 3 Output: 3 Explanation: The smallest answer is N = 111, which has length 3.
Note:
1 <= K <= 10^5