using System;
using System.Linq;
using System.Collections.Generic;
using System.Runtime.InteropServices.ComTypes;

namespace Atcoder01
{
    class Program
    {
        static void Main(string[] args)
        {
            int K = Oneint();
            string S = Onestring();
            string ans = S;

            if(S.Length > K)
            {
                ans = S.Substring(0, K) + "...";
            }


            Console.WriteLine(ans);
        }

        static string Tasu(string a1, string b1)
        {
            int anum = a1.Length;
            int bnum = b1.Length;
            int[] a = Array(a1);
            int[] b = Array(b1);

            string tasustring = "";
            if (anum < bnum)
            {
                int[] tasuans = new int[bnum + 1];
                for (int i = 0; i < anum; i++)
                {
                    tasuans[i] = a[i] + b[i];
                }
                for (int i = anum; i < bnum; i++)
                {
                    tasuans[i] = b[i];
                }
                for (int i = 0; i < tasuans.Length; i++)
                {
                    if (tasuans[i] >= 10)
                    {
                        tasuans[i] -= 10;
                        tasuans[i + 1]++;
                    }
                }
                for (int i = 0; i < tasuans.Length - 1; i++)
                {
                    tasustring = tasuans[i].ToString() + tasustring;
                }
                if (tasuans[tasuans.Length - 1] != 0)
                {
                    tasustring = tasuans[tasuans.Length - 1].ToString() + tasustring;
                }
            }
            else
            {
                int[] tasuans = new int[anum + 1];
                for (int i = 0; i < bnum; i++)
                {
                    tasuans[i] = a[i] + b[i];
                }
                for (int i = bnum; i < anum; i++)
                {
                    tasuans[i] = a[i];
                }
                for (int i = 0; i < tasuans.Length; i++)
                {
                    if (tasuans[i] >= 10)
                    {
                        tasuans[i] -= 10;
                        tasuans[i + 1]++;
                    }
                }
                for (int i = 0; i < tasuans.Length - 1; i++)
                {
                    tasustring = tasuans[i].ToString() + tasustring;
                }
                if (tasuans[tasuans.Length - 1] != 0)
                {
                    tasustring = tasuans[tasuans.Length - 1].ToString() + tasustring;
                }
            }
            return tasustring;
        }

        static int[] Array(string A)
        {
            int[] a = new int[A.Length];
            string num;
            for (int i = 0; i < A.Length; i++)
            {
                num = A.Substring(i, 1);
                a[A.Length - i - 1] = int.Parse(num);
            }

            return a;
        }


        private static string[] Arraystring()
        {
            return Console.ReadLine().Split(' ');
        }

        private static string Onestring()
        {
            return Console.ReadLine();
        }

        private static int Oneint()
        {
            return int.Parse(Console.ReadLine());
        }

        private static int[] Arrayint()
        {
            return Console.ReadLine().Split(' ').Select(int.Parse).ToArray();
        }

        static long[] Arraylong()
        {
            String[] input_line = Console.ReadLine().Split(' ');
            long[] input_num = new long[input_line.Length];
            for (int i = 0; i < input_line.Length; i++)
            {
                input_num[i] = long.Parse(input_line[i]);
            }
            return input_num;
        }
    }
}

Measured memory_bytes: 27552