/*Teodor Nicolae Pintilie
C.N. Andrei Saguna
[email protected]
Clasa a X-a*/
#include <iostream>
#include <fstream>
using namespace std;
void ciur(int n,int v[])
{
    int i, j, nr = 0;
    for (i = 2; i <= n; ++i) {
      if (v[i] == 0) {
        nr++;
        for (j = i + i; j <= n; j += i) {
          v[j] = 1;
        }
      }
    }
  }
int solve(int n,int v[],int k)
{

    for(int i=n;i>0;i--)
   {   int nr_div_prim=0;
       for(int j=2;j<i;j++)
        if(v[j]==0 && i%j==0)
        nr_div_prim++;
        if(nr_div_prim==k)
            return i;
    }
    return 0;
}

int main()
{
    ifstream in("divprim.in");
    ofstream out("divprim.out");
   int a[1001]={0},n,k,t;
    in>>t;
    while(in>>n>>k&&t>0)
    {
    ciur(n,a);
    out<<solve(n,a,k)<<"\n";
  t--;
    }



    return 0;
}