#include <fstream>
#include <vector>
using namespace std;
ifstream cin("divprim.in");
ofstream cout("divprim.out");
const int N = 1000001;
vector <int> a[8];
int nr[N];
int caut(vector <int> v,int n){
    int r  = 0;
    int pas = 1 << 15;
    while(pas!=0){
        if(v[r+pas] <= n && r+pas <= v.size()){
            r+=pas;
        }
        pas /= 2;
    }
    return v[r];
}
int main()
{
    int t,k,i,div,j,n;
    for(i = 2;i < N;i++){
        if(nr[i] == 0){
            for(j=i;j<N;j+=i){
                nr[j]++;
            }
        }
    }
    for(i=1;i<N;i++){
        a[nr[i]].push_back(i);
    }

    cin >> t;
    for(i=0;i<t;i++){
        cin >> n >> k;
        cout << caut(a[k],n) << "\n";
    }
    return 0;
}