Do you know parameters lists?

First, let's discuss and clarify some terminology. When I define a subprogram with a parameter list, each element in that list is referred to as a formal parameter. When I call that subprogram and pass it values or variables, each element in that list is called an actual argument.
 
So...what is the minimum number of actual arguments that need to be provided when I call the following procedure that contains five formal parameters?

PROCEDURE business_as_usual(
  advertising_budget_in   IN      NUMBER
 ,contributions_inout     IN OUT  NUMBER
 ,merge_and_purge_on_in   IN      DATE DEFAULT SYSDATE
 ,obscene_ceo_bonus_out   OUT     NUMBER
 ,cut_corners_in          IN      VARCHAR2 DEFAULT 'WHENEVER POSSIBLE'
)