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

int main() {
    int T;
    scanf("%d", &T);
    while (T--) {
        int n, m;
        scanf("%d%d", &n, &m);
        if (m >= n/2) {
            printf("%I64d\n", (long long)n*(n-1)/2);
            continue;
        }
        long long ans = (long long)(n-m)*m + (long long)m*(m-1) +
            (long long)m*(n-2*m);
        printf("%I64d\n", ans);
    }
    return 0;
}