a-a a-b a-c aaa aab aac aag aan aao aar aau ab- aba abb abc abg abn abo abr abu ac- aca acb acc acg acn aco acr acu ag- aga agb agc agg agn ago agr agu an- ana anb anc ang ann ano anr anu aoa aob aoc aog aon aoo aor aou ar- ara arb arc arg arn aro arr aru au- aua aub auc aug aun auo aur b-u baa bab bac bag ban bao bar bau bba bbb bbc bbg bbn bbo bbr bbu bca bcb bcc bcg bcn bco bcr bcu bga bgb bgc bgg bgn bgo bgr bgu bna bnb bnc bng bnn bno bnr bnu boa bob boc bog bon boo bor bou bra brb brg brn bro brr bru bua bub buc bug bun buo bur buu c-- caa cab cac cag can cao car cau cba cbb cbc cbg cbn cbo cbr cbu cca ccb ccc ccg ccn cco ccr ccu cga cgb cgc cgg cgn cgo cgr cgu cn- cna cnb cnc cng cnn cno cnr cnu co- coa cob coc cog con coo cor cou cra crb crc crg crn cro crr cru cua cub cuc cug cun cuo cur cuu gaa gab gac gag gan gao gar gau gba gbc gbg gbn gbo gbr gbu gca gcb gcc gcg gcn gco gcr gcu gga ggb ggc ggg ggn ggo ggr ggu gna gnb gnc gnn gno gnr gnu goa gob goc gog gon goo gor gou gra grb grc grg grn gro grr gru gu- gua gub guc gug gun guo gur guu naa nab nac nag nan nao nar nau nba nbb nbc nbg nbn nbo nbr nbu nca ncb ncc ncg ncn nco ncr ncu nga ngb ngc ngg ngn ngo ngu nna nnb nnc nng nnn nno nnu no- noa nob noc nog non noo nor nou nra nrb nrc nrg nrn nro nrr nru nua nub nuc nug nun nuo nur nuu oaa oab oac oag oan oao oar oau ob- oba obb obc obg obn obo obr obu oc- oca ocb occ ocg ocn oco ocr ocu oga ogc ogg ogn ogo on- ona onb onc ong onn ono onr onu oo- ooa oob ooc oog oon ooo oor or- ora orb orc org orn oro orr oru ou- oua ouc oun ouo our ra- raa rab rac rag ran rao rar rau rba rbb rbc rbg rbn rbo rbr rbu rca rcb rcc rcg rcn rco rcr rcu rga rgb rgc rgg rgn rgo rgr rna rnb rnc rng rnn rno rnr rnu roa rob roc rog ron roo ror rou rra rrb rrc rrg rrn rrr rru rua rub ruc rug run ruo rur ruu ua- uaa uab uac uag uan uao uar uau uba ubb ubc ubg ubn ubo ubr ubu uca ucb ucc ucg ucn uco ucr ucu uga ugb ugc ugg ugn ugo ugr ugu un- una unb unc ung unn uno unr unu uoa uob uoc uog uon uoo uor ur- ura urb urc urg urn uro urr uru uua uuc uug uun uur uuu