#include <stdio.h>
#include <algorithm>
typedef long long LL;

int n,m;

LL sum(LL l,LL r,LL d){
    return (l+r)*((r-l)/d+1)/2;
}

void solve(){
    scanf("%d%d",&n,&m);
    m = std::min(m,n>>1);
    printf("%lld\n",m+2*sum(n-2*m,n-2,2));
}

int main(){
    int T; scanf("%d",&T);
    while(T--) solve();
}