#include <fstream>
#include<bitset>
using namespace std;
ifstream fin("divprim.in");
ofstream fout("divprim.out");
bitset<1000010>a;
int prime[500005],b[1000005],k,n,t;
void Ciur()
{
    int i,j;
    a[1]=1;
    for(i=4;i<=1000000;i=i+2)
        a[i]=1;
    for(i=3;i*i<=1000000;i=i+2)
        if(a[i]==0)
    for(j=i*i;j<=1000000;j=j+2*i)
        a[j]=1;
    k=1;
    prime[k]=2;
    for(i=3;i<=1000000;i=i+2)
        if(a[i]==0)
        prime[++k]=i;
}
void Formare(int y)
{
    int i,j;
    for(i=1;i<=n;i++)
        b[i]=0;
    for(i=1;prime[i]<=y;i++)
       for(j=prime[i];j<=y;j=j+prime[i])
        b[j]++;

}
int CautBin(int x)
{
    int i;
    for(i=n;i>=1 and b[i]!=x;i--)
        ;
        return i;
}
int main()
{
    int i,t,x,j;
    Ciur();
    fin>>t;
    for(i=1;i<=t;i++)
    {
        fin>>n>>x;
        Formare(n);
        fout<<CautBin(x)<<"\n";
    }
    return 0;
}