Sets & Dictionaries Advanced - 01. Unique Usernames

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;

namespace Advanced
{
    class Program
    {
        static void Main(string[] args)
        {
            var usernames = new HashSet<string>();

            int number = int.Parse(Console.ReadLine());

            for (int i = 0; i < number; i++)
            {
                var input = Console.ReadLine();

                usernames.Add(input);
            }

            foreach (var name in usernames)
            {
                Console.WriteLine(name);
            }
        }
    }
}