For building this game, we will adopt the following straightforward UML diagram:

So far, we have three main components:

• Itontine: Interface for Tontine game functions
• Cplayer: A class for managing players (enrollment, modification, and so on)
• Ctontine: A contract for implementing Tontine game functions

As you'll notice, the interface name starts with an I prefix, whereas contracts starts with a C prefix.

Now, let's talk code.