Solve the programming task below in a Python markdown code block.
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.

Examples

Input

3


Output

180


Input

100


Output

17640