A red cross is made up of five identical squares arranged in a cross pattern: one central square and four squares attached to each of its four sides (top, bottom, left, right). Each square has the same side length. Since the squares are placed edge-to-edge without overlap (each arm square shares only an edge with the central square), the total area is simply the sum of the areas of all five squares.

Hong Kong Red Cross wants to mass produce red crosses, but they do not know how much red material they would need. Given the side length $n$ of each square, can you calculate the area of the red cross?

Input

The input consists of a line with an integer, $n$, the side length of each square in the red cross.

Output

Output an integer, the area of the red cross.

Constraints

$1 \le n \le 100$