using System;
using System.Linq;

namespace Yukicoder
{
    public class Program
    {
        public static void Main(string[] args)
        {
            var score = Console.ReadLine().Split(' ').Select(_ => int.Parse(_)).ToList();
            score.Sort();
            double sum = 0;
            for (int i = 1; i < score.Count -  1; i++)
            {
                sum += score[i];
            }
            sum /= score.Count - 2;
            Console.WriteLine(string.Format("{0:f2}", sum));
        }
    }
}