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 Rust (1.42.0) (judge verdict: Accepted)

use itertools::Itertools;
use proconio::input;
use proconio::marker::{Chars, Usize1};
use std::cmp::*;
use std::collections::*;
use std::iter::Iterator;

#[allow(unused_macros)]
macro_rules! max {
    ($x:expr) => {
      $x
    };
    ($x:expr, $($xs:tt)+) => {
      max($x,max!($($xs)+))
    };
  }

#[allow(unused_macros)]
macro_rules! min {
    ($x:expr) => {
      $x
    };
    ($x:expr, $($xs:tt)+) => {
      min($x,min!($($xs)+))
    };
  }

#[allow(unused_macros)]
macro_rules! debug {
    ($($a:expr),*) => {
        eprintln!(concat!($(stringify!($a), " = {:?}, "),*), $($a),*);
    }
}

fn main() {
  input! {
  n: usize,
  }

  let mut ans = 9;

  if n >= 400 && n <= 599 {
    ans = 8;
  } else if n >= 600 && n <= 799 {
    ans = 7;
  } else if n >= 800 && n <= 999 {
    ans = 6;
  } else if n >= 1000 && n <= 1199 {
    ans = 5;
  } else if n >= 1200 && n <= 1399 {
    ans = 4;
  } else if n >= 1400 && n <= 1599 {
    ans = 3;
  } else if n >= 1600 && n <= 1799 {
    ans = 2;
  } else if n >= 1800 && n <= 1999 {
    ans = 1;
  }

  println!("{}", ans);
}