#include<bits/stdc++.h>
using namespace std;
int a,b,n=1;
long long pown(int x,int y){
	long long n=1;
	for(int i=1;i<=y;i++)n*=x;
	return n;
}
int main(){
	freopen("csp2022pj_pow.in","r",stdin);
	freopen("csp2022pj_pow.out","w",stdout);
	cin>>a>>b;
	if(a>10&&b>9)cout<<-1;
	else if(a==1)cout<<1;
	else if(b==1)cout<<a;
	else if(b==2){
		if(a*a<=1000000000)cout<<a*a;
		else cout<<-1;
	}
	else{
		while(1){
			if(b<=30){
				if(n<b){
					if(pown(a,n)<=1000000000)n++;
					else{cout<<-1;break;}
				}
				if(n=b){
					if(pown(a,n)<=1000000000){
						cout<<pown(a,b);break;
					}
					else{cout<<-1;break;}
				} 
			}
			else cout<<-1;
		}
	}
	return 0;
}