a-a a-b aaa aab aae aak aam aao ab- aba abb abe abk abm abo aea aeb aee aek aem aeo aka akb ake akk akm ako ama amb ame amk amm amo aoa aob aoe aok aom aoo baa bab bae bak bam bao bba bbb bbe bbk bbm bbo be- bea beb bee bek bem beo bka bkb bke bkk bkm bko bma bmb bme bmk bmm bmo boa bob boe bok bom boo eaa eab eae eak eam eao eba ebb ebe ebk ebm ebo eea eeb eee eek eem eeo eka ekb eke eko em- ema emb eme emk emm emo eo- eoa eob eoe eok eom eoo ka- kaa kab kae kak kam kao kba kbb kbe kbk kbm kbo ke- kea keb kee kek kem keo kkb kke kkk kkm kma kmb kme kmk kmm kmo koa kob koe kok kom koo m-o maa mab mae mak mam mao mba mbb mbe mbk mbm mbo mea meb mee mek mem meo mka mkb mke mkk mkm mko mma mmb mme mmk mmm mmo moa mob moe mok mom moo oaa oab oae oak oam oao ob- oba obb obe obk obm obo oea oeb oee oem oeo oka okb oke okk oko om- oma omb ome omm omo oo- ooa oob ook oom ooo