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

public class Test
{
	public static void Main()
	{
		var list = Console.ReadLine()
					.Split(' ')
					.Select(n => int.Parse(n))
					.ToList();
		list.Remove(list.Max());
		list.Remove(list.Min());
		var ans = string.Format("{0:0.00}", (double)list.Average());
		Console.WriteLine(ans);
	}
}