/*
yukicoder No.21
作成者：ヒロソフ
使用言語：C# Ver.
*/
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
 
namespace yukicoder21cs
{
    class Program
    {
        static void Main(string[] args)
        {
            int N, K;
            int[] Nums;
            N = int.Parse(Console.ReadLine());
            K = int.Parse(Console.ReadLine());
            Nums = new int[N];
            for (int i = 0; i < Nums.Length; i++)   Nums[i] =  int.Parse(Console.ReadLine());
            int Min, Max;
            Min = Nums.Min();        //Min = (from c in Nums select c).Min();
            Max = Nums.Max();    //Max = (from c in Nums select c).Max();
            Console.WriteLine(Max - Min);        
        }
    }
}