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 Go (1.6) (judge verdict: Accepted)

package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

var stdin = initStdin()

func initStdin() *bufio.Scanner {
	var stdin = bufio.NewScanner(os.Stdin)
	stdin.Split(bufio.ScanWords)
	return stdin
}

func nextString() string {
	stdin.Scan()
	return stdin.Text()
}

func nextInt() int {
	i, _ := strconv.Atoi(nextString())
	return i
}

func nextInt64() int64 {
	i, _ := strconv.ParseInt(nextString(), 10, 64)

	return i
}

func main() {
	n := nextInt()

	fmt.Println((n - 2) * 180)
}