java: Pat Smith and Kelly Jones are engaged. What are possible last name combinations for the married couple $($listing Pat first$)?$

Run the program below to see three possible married$-$couple names. Note the use of variable firstNames to hold both first names of the couple.

Extend the program to define and use a variable lastName similarly. Note that the print statements are neater. Run the program again.

Extend the program to print two more options that abut the last names, as in SmithJones and JonesSmith. Run the program again.