Problem:
Score : 300 points

Problem Statement

You drew lottery N times. In the i-th draw, you got an item of the kind represented by a string S_i.

How many kinds of items did you get?

Constraints

1 \leq N \leq 2\times 10^5

S_i consists of lowercase English letters and has a length between 1 and 10 (inclusive).

Input

Input is given from Standard Input in the following format:

N
S_1
:
S_N

Output

Print the number of kinds of items you got.

Sample Input 1

3
apple
orange
apple

Sample Output 1

2

You got two kinds of items: apple and orange.

Sample Input 2

5
grape
grape
grape
grape
grape

Sample Output 2

1

Sample Input 3

4
aaaa
a
aaa
aa

Sample Output 3

4

Solution in Go (1.14.1) (judge verdict: Accepted)

package main

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

func main() {
	sc.Split(bufio.ScanWords)
	var N int
	nextInt(&N)
	a := map[string]bool{}
	var ans int
	for i:=0; i<N; i++{
		k := nextLine()
		if a[k] {
			continue
		}
		ans++
		a[k] = true
	}
	fmt.Printf("%d", ans)
}

const MAX_INT int = 1_000_000_000

var sc = bufio.NewScanner(os.Stdin)

var reader = bufio.NewReaderSize(os.Stdin, 1000000)
var writer = bufio.NewWriter(os.Stdout)

func nextLine() string {
	buffer := make([]byte, 0)
	for true {
		line, isPrefix, err := reader.ReadLine()
		if err != nil {
			panic(err)
		}
		buffer = append(buffer, line...)
		if !isPrefix {
			break
		}
	}
	return string(buffer)
}

func nextInt(A ...*int) {
	L := strings.Split(nextLine(), " ")
	for i, a := range A {
		*a, _ = strconv.Atoi(L[i])
	}
}
func nextInts(A *[]int) {
	L := strings.Split(nextLine(), " ")
	(*A) = make([]int, len(L))
	for i, l := range L {
		(*A)[i], _ = strconv.Atoi(l)
	}
}

func nextInt64(A ...*int64) {
	L := strings.Split(nextLine(), " ")
	for i, a := range A {
		*a, _ = strconv.ParseInt(L[i], 0, 64)
	}
}

func max(a int, b int) int {
	if a >= b {
		return a
	}
	return b
}