Extracting last name from a string

If there is always a comma when the last name appears 1st - and NO comma when the last name is last, that will handle them both

	B	C
14	Smith, Brian L	Smith
15	Jones, Evan R	Jones
16	Gray, David S "Buddy"	Gray
17	John Q Smith	Smith
18	Bob Allen Jones	Jones
19	William B Howard	Howard