#include <bits/stdc++.h>
using namespace std;
long long n;
long long power(long long base, long long po) {
  int res = 1;
  while (po != 1) {
    if (po & 1) {
      res *= base;
      po--;
    }
    base *= base;
    po /= 2;
  }
  return res *= base;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cin >> n;
  if (n < 2 || n & 1)
    cout << 0 << "\n";
  else
    cout << power(2, n / 2) << "\n";
}
