#include <bits/stdc++.h>
using namespace std;
long long int i, j, t;
int main() {
  long long int n;
  cin >> n;
  if (n % 2 == 1) {
    cout << "0" << endl;
  } else {
    long long int x = pow(2, n / 2);
    cout << x << endl;
  }
}
