#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(false);
  int64_t n;
  cin >> n;
  if (n % 2 != 0)
    cout << "0" << endl;
  else {
    int64_t k = n / 2;
    int64_t h = 1;
    for (int64_t i = 1; i <= k; i++) {
      h = h * 2;
    }
    cout << h << endl;
  }
}
