You are given an integer N. You have to find smallest multiple of N which consists of digits
1 only. Since this multiple could be large, return it in form of a string.
For N = 55, 110 is smallest multiple consisting of digits 0 and 1. For N = 2, 10 is the answer.
NOTE: You only need to implement the given function. Do not read input, instead use the arguments to the function. Do not print the output, instead return values as specified. Still have a doubt? Checkout Sample Codes for more details.