#include<iostream>
#include<cmath>
using namespace std;
long long a,b;
int main()
{
	cin>>a>>b;
	long long d=a,e=b;
	if(a>1000000000)
	{
		cout<<-1;
		return 0;
	}
	long long ans1,ans2;
	for(ans1=-1; ;ans1++)
	{
		if(d<1)break;
		d/=10;
	}
	ans2=e;
	if(ans1*ans2>9)
	{
		cout<<-1;
		return 0;
	}
	long long ans=a;
	for(int i=2;i<=b;i++)
	{
		ans=ans*a;
	}
	cout<<ans;
	return 0;
 }