#include<bits/stdc++.h>
using namespace std;



int main()
{
    long long int a,b,x,y,z,cas=1;
    while(cin>>a>>b)
    {
        if(a==0 && b==0)
            break;
        x=(a*(a-1))/2;
        y=(b*(b-1))/2;
        z=x*y;
        cout<<"Case "<<cas++<<": "<<z<<endl;
    }
}