#include <iostream>
#include<cstdio>
using namespace std;
int ciur[1000005];
void pr(int N)
{
    int i,j;
    for(i=4;i<=N;i=i+2)
        ciur[i]=ciur[i]+1;
    for(i=3;i<=N;i=i+2)
        if(ciur[i]==0)
            for(j=i;j<N;j=j+i)
                ciur[j]=ciur[j]+1;
    return ;
}
int main()
{
    FILE *in,*out;
    in=fopen("divprim.in","r");
    out=fopen("divprim.out","w");
    int N=1000000,i,n,t,k,l;
    pr(N);
    fscanf(in,"%d",&t);
    for(l=1;l<=t;l++)
    {
        fscanf(in,"%d%d",&n,&k);
        i=n;
        while(ciur[i]!=k)
        {
            i--;
            if(i==1)
            {
                ciur[0]=k;
                i=0;
            }
        }
        fprintf(out,"%d\n",i);
    }
    return 0;
}