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"
)

func main() {
	N := nextInt()
	t := make(map[string]bool)
	count := 0
	for i := 0; i < N; i++ {
		s := nextString()
		if !t[s] {
			count++
		}
		t[s] = true
	}
	fmt.Println(count)
}

func nextInt() int {
	v, _ := strconv.Atoi(nextReader())
	return v
}

func nextInt64() int64 {
	v, _ := strconv.ParseInt(nextReader(), 10, 64)
	return v
}

func nextString() string {
	return nextReader()
}

func nextInts(n int) []int {
	r := make([]int, n)
	for i := 0; i < n; i++ {
		r[i] = nextInt()
	}
	return r
}

func nextInt64s(n int) []int64 {
	r := make([]int64, n)
	for i := 0; i < n; i++ {
		r[i] = nextInt64()
	}
	return r
}

var nextReader func() string

func init() {
	nextReader = NewScanner()
}

func NewScanner() func() string {
	r := bufio.NewScanner(os.Stdin)
	r.Buffer(make([]byte, 1024), int(1e+11))
	r.Split(bufio.ScanWords)
	return func() string {
		r.Scan()
		return r.Text()
	}
}

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

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

func MinA(arg ...int) int {
	var s = arg[0]
	for _, v := range arg {
		s = Min(s, v)
	}
	return s
}

func MaxA(arg ...int) int {
	var s = arg[0]
	for _, v := range arg {
		s = Max(s, v)
	}
	return s
}

func Abs(a int) int {
	if a < 0 {
		return a * -1
	}
	return a
}