#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 5;
const int inf = 1e9 + 1;
const int prime_100000000 = 5761460;
const double eps = 1e-15;
const double EPS = 1e-9;
const double PI = acos(-1.0);
long long gcd(long long a, long long b) {
  if (b == 0) return a;
  return gcd(b, a % b);
}
long long lcm(long long a, long long b) { return a * b / gcd(a, b); }
int main() {
  ios_base ::sync_with_stdio(false);
  cin.tie(NULL);
  long long n;
  cin >> n;
  (n & 1) ? cout << 0 << endl
          : cout << fixed << setprecision(0) << (pow(2, n / 2)) << endl;
}
