#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream in("divprim.in");
ofstream out("divprim.out");
const int nr=1000001;
vector <int> div[nr];
int v[nr];
void ciur()
{
int i,j;
for(i=2;i<=nr;i++)
{
while(v[i]!=0)
i++;
for(j=i;j<=nr;v[j]++,j+=i);
}
for(i=2;i<=nr;i++)
div[v[i]].push_back(i);
}
int caut(int x,int k)
{
int i=-1,pas=1<<19,n=div[k].size();
while(pas!=0)
{
if(i+pas<n && div[k][pas+i]<=x)
i+=pas;
pas/=2;
}
return i;
}
int main()
{
int t,x,k,n,i,j;
ciur();
in>>t;
for(i=0;i<t;i++)
{
in>>x>>k;
n=caut(x,k);
if(n==-1)
out<<0<<"\n";
else
out<<div[k][n]<<"\n";
}
return 0;
}