You have a given integer n. Find the number of ways to fill all 3 × n tiles with the shape described in the picture below. Upon filling, no empty spaces are allowed. Shapes cannot overlap.

<image> This picture describes when n = 4. The left one is the shape and the right one is 3 × n tiles. 

Input

The only line contains one integer n (1 ≤ n ≤ 60) — the length.

Output

Print the number of ways to fill.

Examples

Input


4


Output


4

Input


1


Output


0

Note

In the first example, there are 4 possible cases of filling.

In the second example, you cannot fill the shapes in 3 × 1 tiles.
#include <bits/stdc++.h>
using namespace std;
long long int pw(long long int n, long long int m) {
  long long int sum = 1;
  for (long long int i = 1; i <= m; i++) {
    sum *= n;
  }
  return sum;
}
int main() {
  long long int T, n, i, j, cunt, temp, m, dis, sum, sz, mx, mn;
  cin >> n;
  temp = n * 3;
  if (temp % 2 == 0) {
    n = n / 2;
    cout << pw(2, n) << endl;
    ;
  } else
    cout << "0" << endl;
  return 0;
}
