#include<bits/stdc++.h>
#define ls ch[x][0]
#define rs ch[x][1]
#define ll long long
using namespace std;

inline ll read(){
    ll num=0,neg=1;char c=getchar();
    while(!isdigit(c)){if(c=='-')neg=-1;c=getchar();}
    while(isdigit(c)){num=(num<<3)+(num<<1)+c-'0';c=getchar();}
    return num*neg;
}

ll T,n,m;

int main(){
    T=read();
    while(T--)
    {
        n=read(),m=read();
        if(m>=n/2) printf("%lld\n",n*(n-1ll)/2ll);
        else printf("%lld\n",((n-1ll)+(n-2ll*m))*m);
    }return 0;
}