#include <bits/stdc++.h>
using namespace std;
void solve(istream& in, ostream& out) {
  int n;
  in >> n;
  int res = n % 2 ? 0 : 1LL << (n / 2);
  out << res << endl;
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  std::istream& in(std::cin);
  std::ostream& out(std::cout);
  solve(in, out);
}
