uva 10790

#include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;

long long sum,n,m;

int main()
{
    int cnt = 0 ;
    while (scanf("%lld%lld",&n,&m) != EOF )
    {
        if ( n== 0 && m == 0)
            break;
        sum = (m*(m-1)*n*(n-1))/4;
        printf("Case %d: %lld\n",++cnt,sum);
    }
    return 0;
}