a-a a-b a-c aaa aab aac aad aak aan aau ab- aba abb abc abd abk abn abu ac- aca acb acc acd ack acn acu ad- ada adb adc add adk adn adu aka akb akc akd akk akn aku an- ana anb anc and ank ann anu au- aua aub auc aud auk aun b-u baa bab bac bad bak ban bau bba bbb bbc bbd bbk bbn bbu bca bcb bcc bcd bck bcn bcu bda bdb bdc bdd bdk bdu bka bkb bkc bkk bkn bna bnb bnc bnd bnk bnn bnu bua bub buc bud buk bun buu c-- caa cab cac cad cak can cau cba cbb cbc cbd cbk cbn cbu cca ccb ccc ccd cck ccn ccu cda cdb cdc cdd cdk cdn cdu cka ckb ckc ckd cn- cna cnb cnc cnd cnn cnu cua cub cuc cud cuk cun cuu daa dab dac dad dak dan dau dba dbb dbc dbd dbk dbn dbu dca dcb dcc dcd dck dcn dcu dda ddb ddc ddd ddk ddn ddu dka dkb dkc dkk dku dna dnb dnc dnd dnk dnn dua dub duc dud duk dun ka- kaa kab kac kad kak kan kau kba kbb kbc kbd kbk kbn kbu kca kcb kcc kcd kck kcn kcu kda kdb kdc kdk kdu kkb kkc kkk kkn kku kn- kna knc knd knk knn knu kub kuc kud kuk kun kuu naa nab nac nad nak nan nau nba nbb nbc nbd nbk nbn nbu nca ncb ncc ncd nck ncn ncu nda ndb ndc ndd ndk ndn ndu nka nkc nkk nkn nku nna nnb nnc nnk nnn nnu nua nub nuc nud nuk nun nuu ua- uaa uab uac uad uak uan uau uba ubb ubc ubk ubn ubu uca ucb ucc ucd uck ucn ucu uda udb udc udd udk udn udu uka ukb ukc ukk ukn uku un- una unb unc und unk unn unu uua uuc uun uuu