#include <iostream>
#include <fstream>
#include<math.h>
using namespace std;
ifstream f("progresie.in");
ofstream g("progresie.out");

int main()
{
    int n,t,r,x,y,i,j,ct,k,l,rad;
    f>>t;
    for (i=1;i<=t;i++)
    {
        f>>n>>r;
        j=1;ct=1;
        int ok=1;
        while (ok)
        {
            for (l=j;l<j+ct && ok==1;l++)
            {
                int ratie=0,contor=0;
                rad=(sqrt(l+ratie));
                while ((rad+1)*(rad+1)-l-ratie<=rad+1 && (rad+1)*(rad+1)-l-ratie>=0)
                {
                    ratie=ratie+r;
                    contor++;
                    if (contor==n)
                    {
                        g<<l<<'\n';
                        ok=0;
                        break;
                    }
                }
            }
            j=l+ct;
            ct++;
        }
    }
    return 0;
}