#include<bits/stdc++.h>
#define ywj(a) freopen(#a".in","r",stdin); //freopen(#a".out","w",stdout);
#define wlp ios::sync_with_stdio(false);
#define f1(i,a,b) for(int i=a;i<=b;i++)
#define f2(i,a,b) for(int i=a;i>=b;i--)
#define maxn 1000
using namespace std;

int main(){
	//ywj()
	wlp;
	int a,b;
	int ans;
	cin>>a>>b;
	ans=pow(a,b);
	if(ans<=0) cout<<"-1";
	else cout<<ans;
	return 0;
}