a-a a-b aaa aab aae aaf aam aan aao ab- aba abb abe abf abm abn abo aea aeb aee aef aem aen aeo af- afa afb afe aff afm afn afo ama amb ame amf amm amn amo an- ana anb ane anf anm ann ano aoa aob aoe aof aom aon aoo baa bab bae baf bam ban bao bba bbb bbe bbf bbm bbn bbo be- bea beb bee bef bem ben beo bfa bfb bfe bff bfm bfn bfo bma bmb bme bmf bmm bmn bmo bna bnb bne bnf bnn bno boa bob boe bof bom bon boo eaa eab eae eaf eam ean eao eba ebb ebe ebf ebm ebn ebo eea eeb eee eef eem een eeo ef- efa efb efe eff efm efo em- ema emb eme emf emm emn emo en- ena enb ene enf enm enn eno eo- eoa eob eoe eof eom eon eoo faa fab fae faf fam fan fao fba fbb fbe fbf fbm fbn fbo fea feb fee fef fem fen feo ffa ffe fff ffm ffn ffo fma fmb fme fmf fmm fmn fmo fna fnb fne fnf fnm fnn foa fob foe fof fom fon foo m-f m-o maa mab mae maf mam man mao mba mbb mbe mbf mbm mbo mea meb mee mef mem men meo mfa mfb mfe mff mfm mfn mfo mma mmb mme mmf mmm mmn mmo mna mnb mne mnf mnm mnn mno moa mob moe mof mom mon moo naa nab nae naf nam nan nao nba nbb nbe nbf nbm nbn nbo ne- nea neb nee nef nem nen neo nfa nfb nfe nff nfn nfo nma nmb nme nmm nmn nmo nna nnb nne nnf nnm nnn nno no- noa nob noe nof nom non noo oaa oab oae oaf oam oan oao ob- oba obb obe obf obm obn obo oea oeb oee oef oem oen oeo of- ofa ofb ofe off ofm ofn ofo om- oma omb ome omf omm omn omo on- ona onb one onf onn ono oo- ooa oob oof oom oon ooo