#include <bits/stdc++.h>
using namespace std;
int main() {
  long long t;
  t = 1;
  while (t--) {
    long long n, m, i, j, k, l, w, q, u, v, c;
    cin >> n;
    if (n % 2) {
      cout << 0;
    } else {
      cout << fixed << setprecision(0) << pow(2.0, n / 2);
    }
  }
  return 0;
}
