#include <fstream>

using namespace std;
ifstream in("divprim.in");
ofstream out("divprim.out");
int c[1000005],m[9][1000005];
int main()
{
    int t,n,k,a,b,i;
    in>>t;
    for(a=2; a<=1000000; a+=2)
            c[a]=1;
        for(a=3; a<=1000000; a+=2)
            if(!c[a])
                for(b=a; b<=1000000; b+=a)
                    ++c[b];
    for(i=1;i<=7;i++)
    m[i][0]=0;
    for(i=0;i<=1000000;i++)
    m[0][i]=1;
    for(a=0; a<=7; a++)
        for(b=1; b<=1000000; b++)
            if(c[b]==a)
                m[a][b]=b;
                else m[a][b]=m[a][b-1];
                    
                
    for(i=1; i<=t; i++)
    {
        in>>n>>k;
        if(m[k][n]==0)
        out<<0<<"\n";
        else out<<m[k][n]<<"\n";
            
        
    }
    return 0;
}