#include<iostream>
using namespace std ;
int main ()
{
    long long a , b ; 
    cin >> a >> b ;
    long long mul = 1 ;
    for (int i = 1 ; i <= b ; i ++)
    {
        mul *= a ;
    }
    if (mul >= 1000000000) cout << -1 ;
    else cout << mul ;
    return 0 ;
}