5
(dog,((opossum,(rat,mouse)),(gibbon,(orangutan,(gorilla,(chimp,human))))),((hippo,((cow,(sheep,goat)),(spermwhale,(finwhale,bluewhale)))),((wrhino,irhino),(donkey,horse))));
((dog,((opossum,(rat,mouse)),(gibbon,(orangutan,(gorilla,(chimp,human)))))),(wrhino,(irhino,((hippo,(spermwhale,(finwhale,bluewhale))),(cow,(sheep,goat))))),(donkey,horse));
(opossum,(dog,((hippo,((sheep,(cow,goat)),(spermwhale,(finwhale,bluewhale)))),((wrhino,irhino),(donkey,horse)))),((rat,mouse),(gibbon,(orangutan,(human,(gorilla,chimp))))));
(dog,((opossum,(gibbon,(orangutan,(gorilla,(chimp,human))))),(rat,mouse)),((hippo,(cow,(spermwhale,((sheep,goat),(finwhale,bluewhale))))),(wrhino,(irhino,(donkey,horse)))));
(dog,((opossum,(hippo,((cow,(sheep,goat)),(spermwhale,(finwhale,bluewhale))))),(horse,(donkey,(wrhino,irhino)))),((rat,mouse),(orangutan,(gibbon,(gorilla,(chimp,human))))));
