Dora, the Explorer is standing at the origin of the infinite two-dimensional plane. At the end of every sec, she can move up down , left or right, ie one step in any four directions, by 1 meter. But she thought of challenging herself and decides to move only by 90 degrees after the first step. For example, if she has just moved east or west, the next step she takes has to be either north or south, and vice versa.
Since the sun is about to set, her mom has given permission to take atmost n steps according to the rules above. How many different points can she arrive to at the end? Ignore the final orientation of Dora.

Input

The only line contains a single integer n (1≤n≤1000) - the number of steps Dora makes.

Output

Print a single integer — the number of different possible locations after exactly n steps.

Examples

input 1

1

output 1

4

input 2

2

output 2

4

input 3

3

output 3 

12