Modify the circuit built in Part I by adding any necessary components to produce the following sequence when PB$1,$ the momentarily push button, is left mouse clicked upon and released.

Cylinder $1$ extends;

Cylinder $2$ extends;

Both cylinders retract;

The cycle repeats continuously until a momentarily push button PB$2,$ to be added to the circuit, is clicked upon. It is understood that, when this push button is left clicked upon, the current cycle must complete $($run until both cylinders retract$)$ before stopping.