Possibly three months."
( ( ( Possibly ( three months ) ) . ) '' )
(ROOT (S (VP (VB Possibly) (NP (CD three) (NNS months))) (. .) ('' '')))
Maybe three months. 
( Maybe ( ( three months ) . ) )
(ROOT (X (ADVP (RB Maybe)) (NP (CD three) (NNS months)) (. .)))