using System;

namespace atcorder
{
    class Program
    {
        static void Main()
        {
            var k = int.Parse(Console.ReadLine());
            var s = Console.ReadLine();

            if(s.Length <= k)
            {
                Console.WriteLine(s);
            }
            else
            {
                Console.WriteLine(s.Substring(0,k) + "...");
            }

        }
    }
}

