using System;

public class Program {
	public void Solve() {
		string[] s = Console.ReadLine().Split(' ');
		
		int[] score = new int[s.Length];
		for (int i = 0; i < s.Length; i++) {
			score[i] = int.Parse(s[i]);
		}
		Array.Sort(score);
		
		float sum = 0;
		for (int i = 1; i < score.Length - 1; i++) {
			sum += score[i];
		}
		float ave = sum / (s.Length - 2);
		Console.WriteLine(string.Format("{0:f2}", ave));
	}
	
	public static void Main(string[] args) {
		Program program = new Program();
		program.Solve();
	}
}