using System;

public class Program

{

    public static void Main()

    {

        int x = 7, y = 3;

​

        Console.WriteLine($"  domain: x = {x}, y = {y}\n");

​

        Console.WriteLine($"function: x = y; y = x + y;\n");

        x = y; y = x + y;

        Console.WriteLine($"  result: x = {x}, y = {y}\n");

​

        Console.WriteLine("\n------------------------------\n");

        x = 7; y = 3;

        Console.WriteLine($"  domain: x = {x}, y = {y}\n");

​

        Console.WriteLine($"function: (x, y) = (y, x + y);\n");

        (x, y) = (y, x + y);

        Console.WriteLine($"  result: x = {x}, y = {y}\n");

    }

}