using System;
using System.Collections.Generic;
using System.Text;
class Program
{
    public void Proc()
    {
        Reader.IsDebug = false;
        int numCount = int.Parse(Reader.ReadLine());
        int groupCount = int.Parse(Reader.ReadLine());

        int min = int.MaxValue;
        int max = int.MinValue;

        for (int i = 0; i < numCount; i++)
        {
            int tmp = int.Parse(Reader.ReadLine());
            min = Math.Min(min, tmp);
            max = Math.Max(max, tmp);
        }
        int ans = max - min;
        Console.WriteLine(ans);

    }



    


    public class Reader
    {
        public static bool IsDebug = true;
        private static String PlainInput = @"
 


8
4
329
980
656
738
739
542
873
501



 
";
        private static System.IO.StringReader Sr = null;
        public static string ReadLine()
        {
            if (IsDebug)
            {
                if (Sr == null)
                {
                    Sr = new System.IO.StringReader(PlainInput.Trim());
                }
                return Sr.ReadLine();
            }
            else
            {
                return Console.ReadLine();
            }
        }
        public static int[] GetInt(char delimiter = ' ', bool trim = false)
        {
            string inptStr = ReadLine();
            if (trim)
            {
                inptStr = inptStr.Trim();
            }
            string[] inpt = inptStr.Split(delimiter);
            int[] ret = new int[inpt.Length];
            for (int i = 0; i < inpt.Length; i++)
            {
                ret[i] = int.Parse(inpt[i]);
            }
            return ret;
        }
    }
    static void Main()
    {
        Program prg = new Program();
        prg.Proc();
    }
}