#include <fstream>
#include <cmath>

using namespace std;
ifstream fin("divprim.in");
ofstream fout("divprim.out");

const int Nmax = 1000000;
long long t, n, k, i, j, nr[Nmax+5];
bool ok, v[Nmax+5];

void ciur()
{
    v[0] = 1;
    v[1] = 1;
    for(i=2; i<=Nmax; i++)
        if(!v[i])
        {
            nr[i] = 1;
            for(j=2; i*j<=Nmax; j++)
                {
                    v[i*j] = 1;
                    nr[i*j]++;
                }
        }
}

int main()
{
    fin >> t;
    ciur();
    for(i=1; i<=t; i++)
    {
        fin >> n >> k;
        ok = 0;
        while(nr[n]!=k && n>0)
            n--;
        fout << n << "\n";
    }
    fin.close();
    fout.close();
    return 0;
}