#include <iostream>
using namespace std;

const int N = 1e9;
#define int long long
int a, b, mul = 1;

signed main(){
    cin >> a >> b;
    for(int i = 1; i <= b; i++){
        if(mul >= N){
            cout << -1 << endl;
            break;
        }
        mul *= a;
    }
    cout << mul << endl;
    
    
    return 0;
}

大佬救救我，题目P8813:(