using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace YukiCoder
{
    class Program
    {
        static void Main(string[] args)
        {
            var va = Console.ReadLine().Split().Select(int.Parse).OrderBy(n => n);
            int nc = va.Count();
            double f = va.Skip(1).Take(nc - 2).Average();
            Console.WriteLine(f.ToString("F2"));
            //Console.ReadLine();
        }
    }
}