#include<bits/stdc++.h>
using namespace std;
int main()
{
	long long n,x;
	long long sum = 1;
	cin >>n >> x;
	if(n + x >=20)
	{
		cout << "-1";
	}
	else
	{
		for( int i = 1; i <= n; i++)
		{
			sum *= x;
		}
		cout << sum;
	}
 } 
/**************************************************************
	Problem: 2405
	User: yangwanning
	Language: C++
	Result: Wrong Answer
****************************************************************/