#include <bits/stdc++.h>   using namespace std;   mt19937 rnd(0);   const long long MAXN = 2e6 + 1, MOD = 998244353, M = 1000000001;   signed main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     int t;     cin >> t;     for (; t--;) {       long long n, m;       cin >> n >> m;       long long l = (n - m) / (m + 1);       long long k = n - m - (m + 1) * l;       long long ans = l * (l + 1) * (m + 1 - k) / 2 + k * (l + 1) * (l + 2) / 2;       cout << n * (n + 1) / 2 - ans <<   n ;     }     return 0;   }   