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;

namespace kozaiyApp
{
    public class C
    {
        static void Main()
        {
            int N = int.Parse(Console.ReadLine());
            List<string> ad = new List<string>();
            List<string> eh = new List<string>();
            List<string> il = new List<string>();
            List<string> mp = new List<string>();
            List<string> qu = new List<string>();
            List<string> vz = new List<string>();

            for (int I = 0; I < N; I++)
            {
                string str = Console.ReadLine();

                if (str[0] == ('a' | 'b' | 'c' | 'd'))
                {
                    if (ad.Contains(str))
                    {
                        continue;
                    }
                    else
                    {
                        ad.Add(str);
                    }
                }
                else if (str[0] == ('e' | 'f' | 'g' | 'h'))
                {
                    if (eh.Contains(str))
                    {
                        continue;
                    }
                    else
                    {
                        eh.Add(str);
                    }
                }
                else if (str[0] == ('i' | 'j' | 'k' | 'l'))
                {
                    if (il.Contains(str))
                    {
                        continue;
                    }
                    else
                    {
                        il.Add(str);
                    }
                }
                else if (str[0] == ('m' | 'n' | 'o' | 'p'))
                {
                    if (mp.Contains(str))
                    {
                        continue;
                    }
                    else
                    {
                        mp.Add(str);
                    }
                }
                else if (str[0] == ('q' | 'r' | 's' | 't' | 'u'))
                {
                    if (qu.Contains(str))
                    {
                        continue;
                    }
                    else
                    {
                        qu.Add(str);
                    }
                }
                else
                {
                    if (vz.Contains(str))
                    {
                        continue;
                    }
                    else
                    {
                        vz.Add(str);
                    }
                }

            }

            Console.WriteLine(ad.Count + eh.Count + il.Count + mp.Count + qu.Count + vz.Count);
        }
    }
}