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;
using System.Linq;
 
class D
{
    static void Main()
    {
        int N = int.Parse(Console.ReadLine());
        var A = (Console.ReadLine()).Split(' ').Select(s => long.Parse(s)).ToArray();

        var Sum = 1000L;
        var Stock = 0L;

        for (int i = 0; i < N - 1; i++)
        {
            if (A[i + 1] < A[i])
            {
                Sum += A[i] * Stock;
                Stock = 0;
            }
            else if (A[i + 1] > A[i])
            {
                var now = Sum / A[i];
                
                Sum -= now * A[i];
                Stock += now;
            }
        }
        if (Stock != 0)
        {
            Sum = Sum + A[A.Length - 1] * Stock;
            Stock = 0;
        }
        Console.WriteLine(Sum.ToString());
    }
}