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 Go (1.14.1) (judge verdict: Accepted)

package main

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

/*-----------Main-----------*/

func main() {
	x := readI()
	ans := 0
	switch {
	case x < 600:
		ans = 8
	case x < 800:
		ans = 7
	case x < 1000:
		ans = 6
	case x < 1200:
		ans = 5
	case x < 1400:
		ans = 4
	case x < 1600:
		ans = 3
	case x < 1800:
		ans = 2
	case x < 2000:
		ans = 1
	}
	fmt.Println(ans)
}

/*-----------Utilities-----------*/

var sc = bufio.NewScanner(os.Stdin)

func init() {
	if len(os.Args) >= 2 {
		if os.Args[1] == "debug" {
			debug()
		}
	}
	const maxBuf = 200100
	var buf []byte = make([]byte, maxBuf)
	sc.Split(bufio.ScanWords)
	sc.Buffer(buf, maxBuf)
}

func debug() {
	testFile, err := os.Open("./test/sample-1.in")
	if err != nil {
		fmt.Fprintln(os.Stderr, "Error : There is no testfile.")
		os.Exit(1)
	}
	sc = bufio.NewScanner(testFile)
}

func readS() string {
	sc.Scan()
	return sc.Text()
}

func readSs(a int) []string {
	b := make([]string, a)
	for i := 0; i < a; i++ {
		b[i] = readS()
	}
	return b
}

func readI() int {
	sc.Scan()
	r, _ := strconv.Atoi(sc.Text())
	return r
}

func readIs(a int) []int {
	b := make([]int, a)
	for i := 0; i < a; i++ {
		b[i] = readI()
	}
	return b
}

func readF() float64 {
	sc.Scan()
	r, _ := strconv.ParseFloat(sc.Text(), 64)
	return r
}

func readFs(a int) []float64 {
	b := make([]float64, a)
	for i := 0; i < a; i++ {
		b[i] = readF()
	}
	return b
}

func max(a []int) int {
	l := len(a)
	m := a[0]
	for i := 1; i < l; i++ {
		if a[i] > m {
			m = a[i]
		}
	}
	return m
}

func min(a []int) int {
	l := len(a)
	m := a[0]
	for i := 1; i < l; i++ {
		if a[i] < m {
			m = a[i]
		}
	}
	return m
}

func sortI(a []int) []int {
	sort.Ints(a)
	return a
}

func reverse(a []int) []int {
	l := len(a)
	r := make([]int, l)
	for i := 0; i < l; i++ {
		r[i] = a[l-i-1]
	}
	return r
}

func countI(a []int, b int) int {
	l := len(a)
	var c int
	for i := 0; i < l; i++ {
		if a[i] == b {
			c++
		}
	}
	return c
}