Define the Artist class in Artist.py with a constructor to initialize an artist's information. The constructor should by default initialize the artist's name to "unknown" and the years of birth and death to $-1.$

Define the Artwork class in Artwork.py with a constructor to initialize an artwork's information. The constructor should by default initialize the title to "unknown", the year created to $-1,$ and the artist to use the Artist default constructor parameter values. Add an import statement to import the Artist class.

Add import statements to main.py to import the Artist and Artwork classes.

Ex: If the input is: