a-a a-b a-c aaa aab aac aad aan aau ab- aba abb abc abd abn abu ac- aca acb acc acd acn acu ad- ada adb adc add adn adu an- ana anb anc and ann anu au- aua aub auc aud aun b-u baa bab bac bad ban bau bba bbb bbc bbd bbn bbu bca bcb bcc bcd bcn bcu bda bdb bdc bdd bdu bna bnb bnc bnd bnn bnu bua bub buc bud bun buu c-- caa cab cac cad can cau cba cbb cbc cbd cbn cbu cca ccb ccc ccd ccn ccu cda cdb cdc cdd cdn cdu cn- cna cnb cnc cnd cnn cnu cua cub cuc cud cun cuu daa dab dac dad dan dau dba dbb dbc dbd dbn dbu dca dcb dcc dcd dcn dcu dda ddb ddc ddd ddn ddu dna dnb dnc dnd dnn dua dub duc dud dun naa nab nac nad nan nau nba nbb nbc nbd nbn nbu nca ncb ncc ncd ncn ncu nda ndb ndc ndd ndn ndu nna nnb nnc nnn nnu nua nub nuc nud nun nuu ua- uaa uab uac uad uan uau uba ubb ubc ubn ubu uca ucb ucc ucd ucn ucu uda udb udc udd udn udu un- una unb unc und unn unu uua uuc uun uuu