Parsa is tired of making up stories, so he’ll give you the statement straight. You are given a function f defined as follows:
1. f(1) = 2.
2. If n is even, then f(n) = floor(f(n - 1) / 2) * ceil(f(n - 1) / 2)
3. If n is odd, then f(n) = f(n - 1) - 4.
Given n, output the value of f(n).

Input Format:

The first line an integer n.

Output:

Output f(n).

Sample Input:

8

Sample Output:

2