#include <bits/stdc++.h>
#define ls rt<<1
#define rs rt<<1|1
using namespace std;

typedef unsigned long long ll;
const ll inf = (1ll << 63);
const int maxn = 1000001;


int main()
{
    int t;
    scanf("%d",&t);
    while(t--)
    {
      ll n,m;
      cin>>n>>m;
      m=min(2*m,n-1);
      cout<<min(n*(n-1)/2,(n-1+n-m)*m/2)<<endl;
    }
}