using System;

public class Program

{

    public static void Main()

    {

        double grade1 , grade2 ,grade3 ;

        Console.WriteLine(" 1כתוב ציון");

        grade1 = double.parse(console.ReadLine());

        Console.WriteLine(" 2כתוב ציון");

        grade2 = double.parse(console.ReadLine());

        Console.WriteLine(" 3כתוב ציון");

        grade3 = double.parse(console.ReadLine());

        avg=(grade1+grade2+grade3)/3;

        console.WriteLine("הממוצע"+avg);

    }

}