#include <iostream>
using namespace std;
const int N = 1e9,N1 = 1e5;
long long res = 1;

void func(long long a,long long b)
{
    while(b)
    {
        res *= a;
        b --;
    }
}

int main()
{
    long long n,m;
    cin >> n >> m;
    if(n < N && m == 1) res = n;
    else if(n == 1) res = 1;
    else if(n > N1 || m > N1)  res = N + 1;
    else func(n,m);
    if(res > N) cout << "-1" << endl;
    else cout << res << endl;
    return 0;
}