Score : 100 points

Problem Statement

Given an integer N not less than 3, find the sum of the interior angles of a regular polygon with N sides.

Print the answer in degrees, but do not print units.

Constraints

  • 3 \leq N \leq 100

Input

Input is given from Standard Input in the following format:

N

Output

Print an integer representing the sum of the interior angles of a regular polygon with N sides.


Sample Input 1

3

Sample Output 1

180

The sum of the interior angles of a regular triangle is 180 degrees.


Sample Input 2

100

Sample Output 2

17640