Problem Description

Given an integer $ N $ greater than or equal to $ 3 $. Find the sum of the interior angles of a regular $ N $-sided polygon.

Note that the result should be in degrees, and do not output the unit.

Input Format

The input is given from the standard input in the following format:

$ N $

Output Format

Output an integer representing the sum of the interior angles of a regular $ N $-sided polygon.

Sample Input and Output

Sample Input #1

3

Sample Output #1

180

Sample Input #2

100

Sample Output #2

17640

Notes/Hints

Constraints

• $3 \leq N \leq 100$

Sample Explanation 1

The sum of the interior angles of an equilateral triangle is $ 180 $ degrees.

见题面 Input 部分

见题面 Output 部分