using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
 
namespace ConsoleApplication26
{
    class Program
    {
        static void Main(string[] args)
        {
            double b, c;
            c=0;b=1<<29;
            string line;
            while((line=Console.ReadLine())!=null)
            {
                double a = double.Parse(line);
                if (b < a)
                    b = a;
                if (c > a)
                    c = a;
            }
            Console.WriteLine(b - c);
        }
    }
}
 
 