#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
#include <cmath>
#include <set>
#include <vector>
#include <utility>
#include <stack>
#include <deque>
#include <queue>
#include <string>
#include <cctype>
#include <ctime>
#include <sstream>
#include <map>
//#define LOCAL
#define ll long long
#define maxn 100010
#define maxw 1000005
#define INF 1000000000000000000
using namespace std;

ll n, m;

int main()
{
#ifdef LOCAL
    freopen("data.in.txt", "r", stdin);
    freopen("data.out.txt", "w", stdout);
#endif
    int t; cin >> t;
    while(t--)
    {
        scanf("%lld%lld", &n, &m);
        m = min(m, n/2);
        printf("%lld\n", m*(2*n-2*m-1));
    }
    return 0;
}