#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n;
  cin >> n;
  if (n & 1) {
    cout << 0 << endl;
  } else {
    n = n / 2;
    long long ans = 1;
    while (n--) {
      ans = ans * 2LL;
    }
    cout << ans << endl;
  }
}
