#include <iostream>
#include <cmath>
using namespace std;

long long ans = 1;
const int MAX = 1e9;

int main(){
    long long a;
    long long b;
    cin >> a >> b;
    if(a == 1){
        cout << 1;
        return 0;
    }
    for (int i = 1; i <= b; i ++ ){
        ans *= a;
        if(ans > MAX){
            cout << -1;
            return 0;
        }
    }
    cout << ans;
    return 0;
}