#include <bits/stdc++.h>
using namespace std;
const int MOD = 1e9 + 7;
const int MX = 2e5 + 5;
const long long INF = 1e18;
const long double PI = acos((long double)-1);
template <class T>
inline void array_input(T a[], size_t n) {
  for (size_t i = 0; i < n; i++) cin >> a[i];
}
template <class T>
inline void array_init(T a[], size_t n, T value) {
  for (size_t i = 0; i < n; i++) a[i] = value;
}
template <class a, class b, class c>
inline void bool_print(a flag, b toprint1, c toprint2) {
  if (flag)
    cout << toprint1;
  else
    cout << toprint2;
}
template <class T>
T binExp(T a, T b) {
  T res = 1;
  while (b) {
    if (b % 2) res *= a;
    a *= a;
    b /= 2;
  }
  return res;
}
int main() {
  {
    int n;
    cin >> n;
    cout << ((n % 2) ? 0 : binExp((long long)2, (long long)n / 2));
    cout << '\n';
  }
  return 0;
}
