#include <bits/stdc++.h>
using namespace std;
long long int poww(int a, int b) {
  long long int ans = 1;
  while (b > 0) {
    int lastbit = b & 1;
    if (lastbit == 1) ans = ans * a;
    a = a * a;
    b = b >> 1;
  }
  return ans;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int n;
  cin >> n;
  if (n % 2 != 0)
    cout << 0 << "\n";
  else {
    cout << poww(2, n / 2);
  }
  return 0;
}
