Even Times

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Numerics;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;

namespace solutions
{
    class Program
    {
        public static void Main()
        {
            var count = int.Parse(Console.ReadLine());

            var result = new Dictionary<string, int>();

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

                if (!result.ContainsKey(input))
                {
                    result.Add(input, 0);
                }
                result[input] += 1;
            }

            foreach (var item in result)
            {
                if (item.Value % 2 == 0)
                {
                    Console.WriteLine(item.Key);
                }
            }
        }
    }
}