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: Wrong Answer)

using System;

namespace Atcoder
{
    class Program
    {
        static void Main(string[] args)
        {
            int N = int.Parse(Console.ReadLine());
            string[] vs = new string[N];
            string buffer;
            int count=1;
            bool same = false;
            vs[0] = Console.ReadLine();

            for(int i = 1; i < N; i++)
            {
                buffer = Console.ReadLine();
                for(int j=0; j < count; j++)
                {
                    if (buffer == vs[j]) same = true;
                }
                if (!same)
                {
                    count++;
                    vs[count - 1] = buffer;
                }

            }
            Console.WriteLine("{0}", count);
        }
    }
}