Write a function lastfirst() that takes a list of strings as a parameter. Each string in the list has the format ''Last, First'' where Last is a last name and First is a first name. The function lastfirst() returns a list containing two sublists. The first sublist is a list of all the first names and the second sublist is a list of all the last names. The following shows how the function would be called on an example parameter:
>>> lastfirst([''Gerber, Len'', ''Fox, Kate'', ''Dunn, Bob'']
[[''Len'', ''Kate'', ''Bob''], [''Gerber'', ''Fox'', ''Dunn'']]