#include <iostream>
#include <cstdio>

using namespace std;
int ciur[1000001];
int main()
{
    freopen("divprim.in","r",stdin);
    freopen("divprim.out","w",stdout);
    int n,i,j,nr,k,t,aux;
    cin>>t;
    for(i=2;i*i<=1000000;i++){
        if(ciur[i]==0){
            for(j=i;j<=1000000;j+=i){
                ciur[j]++;
            }
        }
    }
    for(i=1;i<=t;i++){
        cin>>nr>>k;
        aux=nr;
        while(ciur[aux]!=k && aux!=0){
            aux--;
        }
        cout<<aux<<'\n';
    }
    return 0;
}