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

using namespace std;

long long find(long long A){
    long long fact = 1;
    for(long long i = 1; i <= A; i++ )
    {
        fact = fact * i;
        if( fact % A == 0 )
            return i;
    }
    return -1;
}

int main() {
    long long P,Q;
    long long A;

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

    in >> P >> Q;

    A = pow(P,Q);

    out << find(A);

    return 0;
}