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