using System;

namespace yukicoder
{
    class Program
    {
        static void Main(string[] args)
        {
            string[] s = Console.ReadLine().Split(' ');
            double[] a = new double[s.Length];
            double ans = 0;
           for(int i = 0; i < s.Length; i++)
            {
                a[i] = double.Parse(s[i]);
            }
            Array.Sort(a);
            for(int j = 1; j < s.Length - 1; j++)
            {
                ans += a[j];
            }
            ans /= s.Length - 2.00;

            if (ans*0.01==Math.Floor(ans))
            {
                ans = Math.Floor(ans * Math.Pow(10, 2));
            }
            Console.WriteLine(string.Format("{0:0.00}", ans));
        }
    }
}