using System;

​

public class Line

{

    public string text;

}

​

public class Program

{

    public static void Main()

    {

        Line s1 = new Line();

        s1.text = "qwe qw q";

        Line s2 = new Line();

        s2.text = "e wq ewq";

​

        Console.WriteLine("First line: " + s1.text);

        Console.WriteLine("Second line: " + s2.text);

        string[] ss1 = s1.text.Split(new char[] { ' ' });

        string[] ss2 = s2.text.Split(new char[] { ' ' });

​

        int maxLength = 0;

        string maxWorld = "";

        foreach (string world in ss1) {

            if (maxLength < world.Length) {

                maxLength = world.Length;

                maxWorld = world;

            }

        }

​

        int maxLength2 = 0;

        string maxWorld2 = "";

        foreach (string world in ss2) {

            if (maxLength2 < world.Length) {

                maxLength2 = world.Length;

                maxWorld2 = world;

            }

        }

​

        Console.WriteLine("-----------After replalce-----------");

        Console.WriteLine("First line: " + s1.text.Replace(maxWorld, maxWorld2));

        Console.WriteLine("Second line: " + s2.text.Replace(maxWorld2, maxWorld));

    }

}