8 UVA 10790 How Many Points of Intersection?

#include<cstdio> #define ll long long ll a,b; int cas=1; int main() { while(~scanf("%d%d",&a,&b)&&(a||b)) printf("Case %d: %lld ",cas++,a*(a⑴)/2*b*(b⑴)/2); return 0; }