(S (S (BASENP (NNP Mandela)) (VP (VBD was) (VP (VP (VBN hospitalised) (PP (IN for) (BASENP (NN eighteen) (NNS days)))) (COMMA ,) (NP (BASENP (PRPD his) (JJS longest) (NN hospitalisation)) (PP (IN since) (NP (BASENP (NN 1990)) (COMMA ,) (SBAR (WHADVP (WRB when)) (S (BASENP (PRP he)) (VP (VBD was) (VP (VP (VBN released) (PP (IN from) (BASENP (NN prison)))) (PP (IN after) (BASENP (NN 27) (NNS years))))))))))))) (PERIOD .))