#include<bits/stdc++.h>
using namespace std;
#define ll long long
const int N=1e6+3;
ll sum[N];
void cal(){
    for(int i=1;i<N;++i){
        sum[i]=sum[i-1]+i;
    }
}
int main(){
    cal();
    int T;ll n,m;
    scanf("%d",&T);
    while(T--){
        scanf("%lld %lld",&n,&m);
        if(m>n/2) m=n/2;
        ll res=max(0LL,m*(n-1)+(n-2*m)*m);
        printf("%lld\n",res);
    }
    return 0;
}