#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int a[n + 1];
  int i;
  a[0] = 1;
  a[1] = 0;
  for (i = 2; i <= n; i++) {
    a[i] = 2 * a[i - 2];
  }
  cout << a[n] << endl;
  return 0;
}
