every joke is repeated at least four times . 
(ROOT (S (NP (DT every) (NN joke)) (VP (VBZ is) (VP (VBN repeated) (NP (QP (ADVP (IN at) (JJS least)) (CD four)) (NNS times)))) (. .)))
(ROOT (S (NP (DT ) (NN )) (VP (VBZ ) (VP (VBN ) (NP (QP (ADVP (IN ) (JJS )) (CD )) (NNS )))) (. )))