#include<bits/stdc++.h>
using namespace std;
int main(){
	int a,b,s=1;
	cin>>a>>b;
	for(int i=1;i<=b;i++){
		s*=a;
	}
	if(s>1000000000){
		cout<<-1;
	}else{
		cout<<s;	
	}
	
	return 0;
}

/**************************************************************
	Problem: 2405
	User: zzz
	Language: C++
	Result: Wrong Answer
****************************************************************/