#include<iostream>
#include<fstream>
using namespace std;
int main(){
	int t,n,m,lungime,nr;
	ifstream f("progresie.in");
	ofstream g("progresie.out");
	f>>t;
	while(t--)
	{
		f>>n>>m;
		lungime=(n-1)*m+1;
		nr=0;
		for(int lung=1;lung<=lungime;++lung)
		{
			nr=nr+lung+1+lung-2;
			//cout<<nr<<" ";

		}
		g<<nr-lungime+1<<endl;
	}
	//cin.ignore();
	return 0;
}