#include <fstream>

using namespace std;
int f[1000001];
int d[8][1000001];
int n, i, k, t, j;
int main () {
    ifstream fin ("divprim.in");
    ofstream fout("divprim.out");

    for (i=2;i<=1000000;i++)
        if (f[i] == 0)
            for (j=i; j<=1000000;j+=i)
                f[j]++;

    for (k=1;k<=7;k++) {
        d[k][0] = 0;
        for (i=1;i<=1000000;i++) {
            if (f[i] == k)
                d[k][i] = i;
            else
                d[k][i] = d[k][i-1];
        }
    }

    for (fin>>t;t--;) {
        fin>>n>>k;
        fout<<d[k][n]<<"\n";
    }

    return 0;
}