a-a a-b aaa aab aaf aam aao aar aay ab- aba abb abf abm abo abr aby af- afa afb aff afm afo afr afy ama amb amf amm amo amr amy aoa aob aof aom aoo aor ar- ara arb arf arm aro arr ary ay- aya ayf ayo ayr baa bab baf bam bao bar bay bba bbb bbf bbm bbo bbr bby bfa bfb bff bfm bfo bfr bfy bma bmb bmf bmm bmo bmr boa bob bof bom boo bor boy bra brb brf brm bro brr bry by- bya byf bym byo byr faa fab faf fam fao far fay fba fbb fbf fbm fbo fbr ffa fff ffm ffo ffr ffy fma fmb fmf fmm fmo fmr foa fob fof fom foo for foy fra frb frf frm fro frr fry fy- fya fyb fyo m-f m-o m-r maa mab maf mam mao mar may mba mbb mbf mbm mbo mbr mfa mfb mff mfm mfo mfr mfy mma mmb mmf mmm mmo mmr moa mob mof mom moo mor moy mra mrb mrf mrm mro mrr mry my- mya myb myf mym myo myr oaa oab oaf oam oao oar ob- oba obb obf obm obo obr oby of- ofa ofb off ofm ofo ofr om- oma omb omf omm omo omr omy oo- ooa oob oof oom ooo oor or- ora orb orf orm oro orr ory oya oyo ra- raa rab raf ram rao rar ray rba rbb rbf rbm rbo rbr rfa rfb rff rfm rfo rfr rma rmb rmf rmm rmo rmr roa rob rof rom roo ror roy rra rrb rrf rrm rrr ry- rya ryf rym ryo ryr ryy yaa yab yaf yam yao yar yay ybf ybm ybr yby yfa yff yfm yfr yma ymm ymo yob yof yom yoo yor yoy yra yrf yro yyb yyf yyy