#include <bits/stdc++.h>
using namespace std;
double pi = 3.141592653589793238462643383279;
long long pw(long long a, long long b) {
  long long res = 1;
  while (b > 0) {
    res *= a;
    b--;
  }
  return res;
}
void solve() {
  long long n;
  cin >> n;
  if (n & 1) {
    cout << 0 << "\n";
  } else {
    cout << pw(2, (n / 2));
  }
}
int main() {
  solve();
  return 0;
}
