#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  long long int m;
  while (~scanf("%d", &n)) {
    m = 1;
    if (n % 2 == 1) {
      printf("0\n");
    } else {
      int h = n / 2;
      for (int i = 0; i < h; i++) {
        m = 2 * m;
      }
      printf("%lld\n", m);
    }
  }
}
