#P2551. Ones
Ones
Description
Given any integer 0 <= n <= 10000 not divisible by 2 or 5, some multiple of n is a number which in decimal notation is a sequence of 1's. How many digits are in the smallest such a multiple of n?
Input
Each line contains a number n.
Output
Output the number of digits.
3
7
9901
3
6
12
Source
Waterloo local 2001.06.02