666

#include <bits/stdc++.h>
using namespace std;
int main(){
//freopen("pow.in","r",stdin);
//freopen("pow.out","w",stdout);
long long a,s;
cin>>a>>s;
long long q=pow(a,s);
if(a>10&&s>9||q>1000000000||a<0){
cout<<-1;
return 0;
}

cout<<int(pow(a,s));
return 0 ;
}