#include <iostream>
using namespace std;
const int N = 1e9,N1 = 1e5;
long long res = 1;
void func(long long a,long long b)
{
while(b)
{
res *= a;
b --;
}
}
int main()
{
long long n,m;
cin >> n >> m;
if(n < N && m == 1) res = n;
else if(n == 1) res = 1;
else if(n > N1 || m > N1) res = N + 1;
else func(n,m);
if(res > N) cout << "-1" << endl;
else cout << res << endl;
return 0;
}