#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(NULL);
  int n;
  cin >> n;
  vector<long long> ways(n + 1);
  ways[0] = 1;
  if (n % 2 == 0) {
    int tmp = n / 2;
    int i{1};
    while (i <= tmp) {
      ways[i] = ways[i - 1] * 2;
      i++;
    }
    cout << ways[tmp] << "\n";
  } else {
    cout << 0 << "\n";
  }
  return 0;
}
