C++ :

#include<cstdio>
#include<algorithm>
int a,b;
bool check(long long x)
{
    for (int idx=x%10; x; x/=10)
        if (x%10!=idx)
            return 0;
    return 1;
}
long long solve(long long x)
{
    while (1)
        if (check(x))
            if (x%5==0)
                x+=a+b;
            else
                x+=b;
        else if (x%5==0)
            x+=a;
        else
            break;
    return x;
}
int main()
{
    int t;
    scanf("%d",&t);
    for (int cas=1; cas<=t; cas++)
    {
        scanf("%d%d",&a,&b);
        printf("Case #%d: ",cas);
        if (a%10==0 || a%25==0 || a==35)
        {
            puts("INF");
            continue;
        }
        if (a%5==0 && b%5==0)
        {
            puts("INF");
            continue;
        }
        if (a%5==0)
        {
            long long ans=0;
            for (int i=0; i<=10000; i+=5)
            {
                long long j=5;
                while (j<i)
                    j=j*10+5;
                while ((j-i)%a!=0)
                    j=j*10+5;
                ans=std::max(ans,j+a+b);
            }
            int tmp=9999+b;
            if (tmp%5==0)
            {
                long long j=5;
                while (j<tmp)
                    j=j*10+5;
                while ((j-tmp)%a!=0)
                    j=j*10+5;
                ans=std::max(ans,j+a+b);
            }
            printf("%lld\n",ans);
            continue;
        }
        long long ans=0;
        for (int i=1; i<=10000; i++)
            ans=std::max(ans,solve(i));
        printf("%lld\n",ans);
    }
    return 0;
}