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.Collections.Generic;
using static System.Console;

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            int n = int.Parse(ReadLine());
            var s = new LinkedList<string>();
            int ans = 0;

            for (int i = 0; i < n; i++)
            {
                string present = ReadLine();
                if (s.Contains(present))
                {
                    continue;
                }
                else
                {
                    s.AddFirst(present);
                    ans++;
                }
            }
            Write(ans);
        }
    }
}