using System;

namespace yukicoder
{
    class Program
    {
        static void Main(string[] args)
        {
            int a = int.Parse(Console.ReadLine());
            int b = int.Parse(Console.ReadLine());
            string[] s = new string[a];
            double[] s1 = new double[a];
            double ans = 0;
            for (int i = 0; i <a; i++)
            {
              s[i] = Console.ReadLine();
                s1[i] = double.Parse(s[i]);
            }
           for(int i = 0; i < a; i++)
            {
                for(int j = 0; j < a ; j++)
                {
                    double x;
                    if (s1[j] <= s1[i])
                    {
                        x = s1[j];
                        s1[j] = s1[i];
                        s1[i] = x;
                    }
                }
        
            }
            ans = s1[0] - s1[a-1];
            Console.WriteLine(ans);
        }   
        }
    }