Light OJ 1078

#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
int main()
{
    int t;
    scanf("%d",&t);
    for(int kase = 1; kase <= t; ++kase)
    {
        LL n, w;
        scanf("%lld %lld",&n, &w);
        LL cnt = 1, ret = w % n;
        while(ret)
        {
            ret = ((ret * 10) % n + (w % n)) % n;
            cnt ++;
            //cout << ret << endl;
        }
        printf("Case %d: %lld\n",kase, cnt);
    }
}