impossible as it may sound 
(ROOT (ADJP (ADJP (JJ impossible)) (SBAR (IN as) (S (NP (PRP it)) (VP (MD may) (VP (VB sound)))))))
(ROOT (ADJP (ADJP (JJ )) (SBAR (IN ) (S (NP (PRP )) (VP (MD ) (VP (VB )))))))