#include<bits/stdc++.h>
signed main()
{
    int test;
    for ( scanf("%d",&test);test--; )
    {
        int n,m;scanf("%d%d",&n,&m);
        m=std::min(m,n/2);
        printf("%lld\n",1LL*m*(2*n-2*m-1));
    }
}