using System;
using System.Linq;

class Program
{
    public void Solve()
    {
        int N = int.Parse(Console.ReadLine());
        int K = int.Parse(Console.ReadLine());
        int[] n = new int[N];
        for (int i = 0; i < n.Length; i++)
        {
            n[i] = int.Parse(Console.ReadLine());
        }
        Array.Sort(n);
        Console.WriteLine(n[n.Length - 1] - n[0]);
    }

    static void Main()
    {
        var solver = new Program();
        solver.Solve();
    }
}