#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  if (n % 2 == 1) {
    cout << 0;
  } else {
    int ans = 1;
    for (int i = 0; i < n / 2; ++i) {
      ans = ans * 2;
    }
    cout << ans;
  }
  return 0;
}
