# optional arguments
def user_names(first_name, last_name, middle_name = ""):
    if middle_name:
        full_name = first_name + " " + middle_name + " " + last_name + "."
        return full_name
    else:
   
        full_name = first_name + " " + last_name + "."
        return full_name
        
musician = user_names("Omari", "hardwick", "jj")
print(musician)