#include <iostream>
#include <fstream>
#include <vector>
using namespace std;

const int MAXN = 1000000;
int divp[MAXN + 1];
int ans[8][MAXN + 1];

int main()
{
    ifstream f("divprim.in");
    ofstream g("divprim.out");

    for (int i = 2; i <= MAXN; i++)
    {
        if (divp[i] == 0)
        {
            for (int j = i; j <= MAXN; j += i)
            {
                divp[j]++;
            }
        }
    }

    for (int k = 0; k <= 7; k++)
    {
        int last = 0;
        for (int i = 1; i <= MAXN; i++)
        {
            if (divp[i] == k)
            {
                last = i;
            }
            ans[k][i] = last;
        }
    }

    int T;
    f >> T;

    for (int t = 0; t < T; t++)
    {
        int N, K;
        f >> N >> K;
        g << ans[K][N] << '\n';
    }

    return 0;
}