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++14 (GCC 5.4.1) (judge verdict: Accepted)

#include <bits/stdc++.h>
using namespace std;
 
typedef long long LL;
typedef pair<int, int> PII;
typedef vector<int> VI;
#define MP make_pair
#define PB push_back
#define X first
#define Y second
 
#define FOR(i, a, b) for(int i = (a); i < (b); ++i)
#define RFOR(i, b, a) for(int i = (b) - 1; i >= (a); --i)
#define ITER(it, a) for(__typeof(a.begin()) it = a.begin(); it != a.end(); ++it)
#define ALL(a) a.begin(), a.end()
#define SZ(a) (int)((a).size())
#define FILL(a, value) memset(a, value, sizeof(a))
#define debug(a) cout << #a << " = " << a << endl;

const double PI = acos(-1.0);
const LL INF = 1e9 + 47;
const LL LINF = INF * INF;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

int main()
{
	ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
	//freopen("In.txt", "r", stdin);
	//freopen("In.txt", "w", stdout);
	
	int n;
	cin >> n;
	cout << 180 * (n- 2);
	
	
	cerr << "Time elapsed: " << clock() / (double)CLOCKS_PER_SEC << endl;
	return 0;
}