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 (GCC 5.4.1) (judge verdict: Accepted)

/*
 * main.c
 *
 *  Created on: 2019/06/02
 *      Author: family
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>

int main()
{
	int N = 0;
	scanf("%d", &N);
	printf("%d\n",180*(N-2));
    return 0;
}