#include <bits/stdc++.h>
using namespace std;
long long binpow(long long a, long long b) {
  if (b == 0) return 1;
  long long res = binpow(a, b / 2);
  if (b % 2)
    return res * res * a;
  else
    return res * res;
}
void solvethetestcase() {
  long long n;
  cin >> n;
  long long f[n + 1];
  f[0] = 1;
  f[1] = 0;
  for (long long i = 2; i <= n; i++) {
    f[i] = 2 * f[i - 2];
  }
  cout << f[n] << "\n";
}
signed main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  long long t = 1;
  for (long long i = 0; i < t; i++) {
    solvethetestcase();
  }
}
