#include"bits/stdc++.h"
using namespace std;
template<class T1,class T2> bool cmax(T1 &x,const T2 &y) { if (x<y) { x=y; return 1; }return 0; }
typedef long long ll;
#define all(x) (x).begin(),(x).end()
int main()
{
	ios::sync_with_stdio(0); cin.tie(0);
	int T; cin>>T;
	int N=2e5;
	vector<ll> f(N+1);
	{
		ll m,n,x;
		auto cal=[&](ll x)
			{
				ll len=(x+m)/(m+1);
				return ((n+x+1ll)*(n-x)+m*(x+x-(len-1)*(m+1))*len)/2;
			};
		for (m=1,n=1e8,x=1; m<=N; m++)
		{
			if (cal(x)<=cal(x+1)) ++x;
			f[m]=x;
			// if (cal(x)<=cal(x-1)) ++x;
		}
	}
	while (T--)
	{
		ll n,m,i;
		cin>>n>>m;
		ll ans=0;
		auto cal=[&](ll lst)
			{
				ll x=min(n,(m+1)*m/2);
				x=(x-lst)/(m+1)*(m+1)+lst;
				ll len=(x-lst)/(m+1)+1;
				ll res=((n+x+1ll)*(n-x)+m*(x+lst)*len)/2;
				ans=max(ans,res);
				return res;
			};
		ll tmp=(m+1)*m/2%(m+1);
		ll l=0,r=min({n,m-1,tmp-5}),m1,m2;
		while (r-l>=500)
		{
			m1=(l+l+r)/3;
			m2=(l+r+r)/3;
			if (cal(m1)<cal(m2)) l=m1; else r=m2;
		}
		for (i=l; i<=r; i++) cal(i);
		l=min({n,m-1,tmp+5}),r=min({n,m-1}),m1,m2;
		while (r-l>=500)
		{
			m1=(l+l+r)/3;
			m2=(l+r+r)/3;
			if (cal(m1)<cal(m2)) l=m1; else r=m2;
		}
		for (i=l; i<=r; i++) cal(i);
		for (i=tmp-100; i<=tmp+100; i++)
		{
			ll x=max(i,0ll);
			x=min({x,n,m-1});
			cal(x);
		}
		cout<<ans<<'\n';
	}
}