Problem:
Score: 100 points

Problem Statement

M-kun is a competitor in AtCoder, whose highest rating is X.

In this site, a competitor is given a kyu (class) according to his/her highest rating. For ratings from 400 through 1999, the following kyus are given:

From 400 through 599: 8-kyu

From 600 through 799: 7-kyu

From 800 through 999: 6-kyu

From 1000 through 1199: 5-kyu

From 1200 through 1399: 4-kyu

From 1400 through 1599: 3-kyu

From 1600 through 1799: 2-kyu

From 1800 through 1999: 1-kyu

What kyu does M-kun have?

Constraints

400 \leq X \leq 1999

X is an integer.

Input

Input is given from Standard Input in the following format:

X

Output

Print the kyu M-kun has, as an integer.
For example, if he has 8-kyu, print 8.

Sample Input 1

725

Sample Output 1

7

M-kun's highest rating is 725, which corresponds to 7-kyu.

Thus, 7 is the correct output.

Sample Input 2

1600

Sample Output 2

2

M-kun's highest rating is 1600, which corresponds to 2-kyu.

Thus, 2 is the correct output.

Solution in C# (.NET Core 3.1.201) (judge verdict: Runtime Error)

using System;
class Program
{
    static void Main(string[] args)
    {
        string[] NK = Console.ReadLine().Split(' ');
        int N = int.Parse(NK[0]);
        int K = int.Parse(NK[1]);
        string[] Ai = Console.ReadLine().Split(' ');
        int[] A = new int[N + 1];
        for (int i = 1; i <= N; i++)
            A[i] = int.Parse(Ai[i - 1]);
        int[] H = new int[N + 1];
        string[] output = new string[N + 1];
        for (int i = K; i <= N; i++)
        {
            int h = A[i];
            for (int j = i - K + 1; j <= i; j++)
            {
                h += A[j];
            }
            H[i] = h;
            if (i > K)
            {
                if (H[i] > H[i - 1])
                    output[i] = "Yes";
                else
                    output[i] = "No";
            }
        }

        for (int i = K + 1; i <= N; i++)
            Console.WriteLine(output[i]);
    }
}