what an idea , what a thrill ride . 
(ROOT (SBAR (WHNP (WDT what) (DT an) (NN idea)) (, ,) (WHNP (WP what) (DT a) (NN thrill) (NN ride)) (. .)))
(ROOT (SBAR (WHNP (WDT ) (DT ) (NN )) (, ) (WHNP (WP ) (DT ) (NN ) (NN )) (. )))