using System;

public class Program

{

    public static void Main()

    {

        double x = 20, y = 3.5, z = 4;

        double otg;

        otg = x + y; Console.WriteLine("x + y = " + otg);

        otg = x - y; Console.WriteLine("x - y = " + otg);

        otg = x * y; Console.WriteLine("x * y = " + otg);

        otg = x / y; Console.WriteLine("x / y = " + otg);

        otg = y / z; Console.WriteLine("y / z = " + otg);

        otg = x / z; Console.WriteLine("x / z = " + otg);

        otg = x / 6; Console.WriteLine("x / 6 = " + otg);

    }

}