using System;
using System.Collections.Generic;
class Program
{
    static void Main(string[] args)
    {
        string[] input = Console.ReadLine()!.Split(' ');
        List<double> numList = new List<double>();
        
        for (int i = 0; i < input.Length; i++)
        {
            numList.Add(double.Parse(input[i]));
        }
        numList.Sort();

        numList.Remove(numList[0]);
        numList.Remove(numList[numList.Count - 1]);

        double sum = 0;
        for (int i = 0; i < numList.Count;i++)
        {
            sum += numList[i];
        }

        double ans = sum / numList.Count;
        Console.WriteLine(ans.ToString("0.00"));
    }
}