Problem:
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

Solution in C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;

namespace ConsoleApp1
{
	class Program
	{
		static void Main(string[] args)
		{
			var n = int.Parse(Console.ReadLine());
			Console.WriteLine(180 * (n - 2));
		}
	}
}