Light Oj 1294

#include<stdio.h>
#include<stdlib.h>
#include<stdbool.h>
#include<math.h>
#include<string.h>
#include<ctype.h>

int main() {
    int t, i;
    scanf("%d", &t);
    for(i=1; i<=t; i++) {
        long long int n, m, j, c=0, sum=0;
        scanf("%lld %lld", &n, &m);
        n/=2;
        sum=n*m;
        printf("Case %d: %lld\n", i, sum);
    }
    return 0;
}