#include <bits/stdc++.h>
using namespace std;
#define int long long
int qpow(int a,int b)
{
	int sum=1;
	while(b!=0)
	{
		if(b&1 !=0)
			sum*=a;
		b>>=1;
		a*=a;
		if(sum>1000000000)
			return -1;
	}
	return sum;
}
signed main()
{
	int a,b;
	cin >> a >> b;
	if(b>30 && a>1)
	{
		cout << -1 << endl;
		return 0;
	}
	cout << qpow(a,b) << endl;
	return 0;
}

WA on #19，民间数据 AC