#include<bits/stdc++.h>
using namespace std;
const unsigned long long N=1e9;
unsigned long long qpow(unsigned long long a,unsigned long long b){
	if(b==1)return a;
	if(b%2==0){
		unsigned long long t=qpow(a,b/2);
		return t*t;
	}
	return qpow(a,b-1)*a;
}
unsigned long long a,b,x;
int main(){
	freopen("csp2022pj_pow.in","r",stdin);
	freopen("csp2022pj_pow.out","w",stdout);
	cin>>a>>b;
	if(a>N||b>N){
		cout<<-1;
		return 0;
	}
	x=qpow(a,b);
	if(x<=0||x>N)cout<<-1;
	else cout<<x;
	return 0;
}