#include<bits/stdc++.h>
using namespace std;
int n,m;
long long ans;
void solve(){
    scanf("%d%d",&n,&m);
    if(m*2>n)m=n/2;
    ans=1ll*m*(2*n-2*m-1);
    printf("%lld\n",ans);
}
int main(){
    int t;scanf("%d",&t);
    for(;t;--t)solve();
    return 0;
}