#include <bits/stdc++.h>
using namespace std;
const long long int INF = 1e18;
int32_t main() {
  long long int n;
  cin >> n;
  if (n % 2 != 0) {
    cout << 0 << "\n";
    return 0;
    ;
  }
  long long int k = pow(2, n / 2);
  cout << k << "\n";
  return 0;
  ;
}
