#include <bits/stdc++.h>
using namespace std;
int n, dp[69];
int main() {
  scanf("%d", &n);
  dp[0] = 1;
  dp[1] = 0;
  for (int i = 2; i < n + 1; ++i) dp[i] = 2 * dp[i - 2];
  printf("%d", dp[n]);
}
