#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  if (n % 2 != 0)
    cout << "0";
  else {
    int g = n / 2;
    double q, w;
    q = g;
    w = 2;
    long long int h = pow(w, q);
    cout << h;
  }
  return 0;
}
