using System;

public class MathOperation

{

    public double a; public double b;

    public MathOperation(){}

    public MathOperation(double a,double b){this.a=a; this.b=b;}

    public int Sbor2(int a, int b)

    {return a*a+b*b;}

    public double Sub2(double a, double b)

    {return a*a-b*b;}

    public double SrSt(double a, double b)

    {return (a+b)/2;}

    public double SrKv(double a, double b)

    {return Math.Sqrt((a*a+b*b)/2);}

}               

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Въведи а:");

        double a = double.Parse(Console.ReadLine());

        Console.WriteLine("Въведи b:");

        double b = double.Parse(Console.ReadLine());

        MathOperation s = new MathOperation(a,b);

        Console.WriteLine("Сбора от квадратите:" + s.Sbor2((int)a,(int)b));

        Console.WriteLine("Разликата от квадратите:" + s.Sub2(a,b));

        Console.WriteLine("Средна стойност:" + s.SrSt(a,b));

        Console.WriteLine("Средно квадратично:" + s.SrKv(a,b));

    }

}