No, I don't know. 
( No ( , ( I ( ( ( do n't ) know ) . ) ) ) )
(ROOT (S (INTJ (UH No)) (, ,) (NP (PRP I)) (VP (VBP do) (RB n't) (VP (VB know))) (. .)))
I do not know.
( I ( ( ( do not ) know ) . ) )
(ROOT (S (NP (PRP I)) (VP (VBP do) (RB not) (VP (VB know))) (. .)))