#include<fstream>
#include<vector>
#include<algorithm>
using namespace std;
ifstream fin("divprim.in");
ofstream fout("divprim.out");
int a[1000002], f[1000002], sol[1000002][9];
int i, j, t, n, k;

int main(){
    for(i=2;i<=1000;i++)
    {
        for(j=i+i;j<=1000000;j+=i)
        {
            f[j]=1;
        }
    }
    for(i=2;i<=1000;i++)
    {
        if(f[i]==0)
            for(j=i;j<=1000000;j+=i)
                a[j]++;
        for(j=1;j<=7;j++)
        {
            if(a[i]==j)
                sol[i][j]=i;
            else
                sol[i][j]=sol[i-1][j];
        }
    }
    /*for(i=1;i<=20000;i++)
    {
        fout<<i<<" "<<f[i]<<" "<<a[i]<<"   ";
        for(j=1;j<=7;j++)
                fout<<sol[i][j]<<" ";
        fout<<"\n";
    }
    */
    fin>>t;
    for(i=1;i<=t;i++)
    {
        fin>>n>>k;
        fout<<sol[n][k]<<"\n";
    }
    fin.close();
    fout.close();
    return 0;
}