#include <iostream>
#include <fstream>
using namespace std;
int fr[1000001],i,j,d,n,k,t;
ofstream g("divprim.out");
int main()
{
    freopen("divprim.in","r",stdin);
    for(i=2;i*i<=1000000;i++)
            if(fr[i]==0)
                    for(d=i;d<=1000000;d=d+i)
                            fr[d]++;
    scanf("%d",&t);
    for(i=1;i<=t;i++)
    {
        scanf("%d%d",&n,&k);
        j=n;
        while(fr[j]!=k&&j>0)
        j--;
        g<<j<<'\n';
            }
    return 0;
}