#include <bits/stdc++.h>
using namespace std;
const long long mod = 1e9 + 7;
const long long N = 1e6 + 5;
int main() {
  long long temp, n;
  cin >> n;
  temp = n;
  if (n % 2 == 1) {
    cout << "0";
    return 0;
  }
  cout << (long long)pow(2, n / 2);
  return 0;
}
