CONCATE - Integer Concatenation
You are given two positive integers N and M. Your task is to find the least positive integer X such that
if N is concatenated X times it becomes divisible by M. if no such positive integer exists print -1 instead.
For example if 12 is concatenated 2 times it becomes 1212.
Given 1<=N<=1000000000 and 1<=M<=100000
Input
First line contains the number of test cases 1<=T<=20. Each of the following T lines contains 2 integers N and M.
Output
For each test case print in a separate line the required value of X or -1 if no such X exists.
Example
Input: 4 2 9 121 11 1 2 35 98765 Output: 9 1 -1 9876
Added by: | Mahesh Chandra Sharma |
Date: | 2011-01-09 |
Time limit: | 1s |
Source limit: | 50000B |
Memory limit: | 1536MB |
Cluster: | Cube (Intel G860) |
Languages: | All |
Resource: | Based on a topcoder problem |