using System;

using System.Linq;

public class Program

{

    public static void Main()

    {

        double avarage = 0.0;

        int sum = 0;

        int[] arr = Console.ReadLine().Split(' ').Select(int.Parse).ToArray();

        foreach (int temperature in arr)

            sum = sum + temperature;

        avarage =(double) sum/arr.Length;

        Console.WriteLine("Средна оценка: {0}", avarage);

    }

}