a-a a-b a-c aaa aab aac aam aao aar aay ab- aba abb abc abm abo abr aby ac- aca acb acc acm aco acr acy ama amb amc amm amo amr amy aoa aob aoc aom aoo aor ar- ara arb arc arm aro arr ary ay- aya ayc ayo ayr baa bab bac bam bao bar bay bba bbb bbc bbm bbo bbr bby bca bcb bcc bcm bco bcr bcy bma bmb bmc bmm bmo bmr boa bob boc bom boo bor boy bra brb brm bro brr bry by- bya byc bym byo byr c-- caa cab cac cam cao car cay cba cbb cbc cbm cbo cbr cby cca ccb ccc ccm cco ccr cma cmb cmc cmm cmo cmr cmy co- coa cob coc com coo cor coy cra crb crc crm cro crr cry cya cyb cyc cym cyo cyr m-o m-r maa mab mac mam mao mar may mba mbb mbc mbm mbo mbr mc- mca mcb mcc mcm mco mcr mma mmb mmc mmm mmo mmr moa mob moc mom moo mor moy mra mrb mrc mrm mro mrr mry my- mya myb myc mym myo myr oaa oab oac oam oao oar ob- oba obb obc obm obo obr oby oc- oca ocb occ ocm oco ocr om- oma omb omc omm omo omr omy oo- ooa oob ooc oom ooo oor or- ora orb orc orm oro orr ory oya oyo ra- raa rab rac ram rao rar ray rba rbb rbc rbm rbo rbr rca rcb rcc rcm rco rcr rma rmb rmc rmm rmo rmr roa rob roc rom roo ror roy rra rrb rrc rrm rrr ry- rya ryc rym ryo ryr ryy yaa yab yac yam yao yar yay ybc ybm ybr yby yca ycc yco ycy yma ymc ymm ymo yob yoc yom yoo yor yoy yra yrc yro yyb yyc yyy