using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Въведи име:");

        string firstName = Console.ReadLine();

        Console.WriteLine();

        Console.WriteLine("Въведи фамилия:");

        string lastName = Console.ReadLine();

        Console.WriteLine();

        string greet  = "Здравей, " + firstName + " " + lastName + "!";

        Console.WriteLine(greet);

        Console.WriteLine();

        string fixedText = greet.Replace(firstName, "Иван");

        Console.WriteLine(fixedText);

        /*Console.WriteLine();

        int length = name.Length;

        Console.WriteLine(length);

        Console.WriteLine();

        int index = greet.IndexOf("А"); 

        Console.WriteLine(index);*/

    }

}