public class Program
{
    public static void Main()
    {
        int num = int.Parse(Console.ReadLine() ?? string.Empty);
        //string[] str = (Console.ReadLine() ?? string.Empty).Trim().Split(' ');
        //string str = Console.ReadLine() ?? string.Empty;

        string n = "";
        for (int i = 0; i < num; i++)
        {
            string str = Console.ReadLine() ?? string.Empty;
            n += str;
        }
        Console.WriteLine(n);
    }
}