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 C# (.NET Core 3.1.201) (judge verdict: Time Limit Exceeded)

using System;
using System.Collections.Generic;
using System.Linq;

class Progaram
{
    static void Main(string[] args)
    {
        var n = Int32.Parse(Console.ReadLine());
        var sl = new List<String>[26];
        var res = 0;
        for (var i = 0; 26 > i; i++)
        {
            sl[i] = new List<String>();
        }
        for (var i = 0; n > i; i++)
        {
            var s = Console.ReadLine();
            var sc = s.ToCharArray();
            var f = (Int32)sc[0] - (Int32)'a';
            if (!sl[f].Contains(s))
            {
                sl[f].Add(s);
                res++;
            }
        }
        Console.WriteLine(res);
    }
}