using System;
using System.Collections.Generic;

namespace CA_TimusRu
{
    class Program1496
    {
        static void Main(string[] args)
        {
            Dictionary<string, int> dict = new Dictionary<string, int>();
            int n = int.Parse(Console.ReadLine());
            for (int i = 0; i < n; i++)
            {
                string s = Console.ReadLine();
                if (dict.ContainsKey(s))
                    dict[s]++;
                else
                    dict.Add(s, 1);
            }

            foreach (var item in dict)
            {
                if (item.Value >= 2)
                    Console.WriteLine(item.Key);
            }
        }
    }
}