#include <bits/stdc++.h>
using namespace std;
int main()
{
freopen("pow.in","r",stdin);
freopen("pow.out","w",stdout);
double a,b;
int m;
cin>>a>>b;
int c=a;
for(int i=2;i<=b;i++)
{
a=a*c;
}
if(a>1000000000)
{
cout<<"-1";
}
else
{
cout<<a;
}
return 0;
}