#include <iostream>
#include <fstream>
#include <cmath>

using namespace std;

long long find(long long P, long long Q){
    long long fact = 1;

    for(long long i = 1; i <= pow(P,Q); i++ )
    {
        fact = fact * i;
        while(fact % P == 0)
        {
            Q--;
            fact = fact/P;
        }

        if(Q == 0)
        {
            return i;
        }
    }
    return -1;
}

int main() {
    long long P,Q;

    ifstream in("gfact.in");
    ofstream out("gfact.out");

    in >> P >> Q;

    out << find(P,Q);

    return 0;
}