using System;

public class Student

{ public string klas;

 public int nomer;

 public double bel;

 public double ae;

 public double math,average;

}

public class Program

{

    public static void Main()

    {

        Student adi=new Student();

        Console.WriteLine("Клас");

        adi.klas= Console.ReadLine();

        Console.WriteLine("Номер:");

        adi.nomer=int.Parse(Console.ReadLine());

        Console.WriteLine("Бел");

        adi.bel=double.Parse(Console.ReadLine());

        Console.WriteLine("Английски");

        adi.ae = double.Parse(Console.ReadLine());

    Console.WriteLine("Математика");

        adi.math=double.Parse(Console.ReadLine());

        adi.average= (adi.bel+adi.ae+adi.math)/3;

        Console.WriteLine(adi.average);

    }

}