Score : 100 points
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.
Input is given from Standard Input in the following format:
N
Print an integer representing the sum of the interior angles of a regular polygon with N sides.
3
180
The sum of the interior angles of a regular triangle is 180 degrees.
100
17640