a-a a-b a-z aaa aab aam aao aar aaz ab- aba abb abm abo abr abz ama amb amm amo amr amz aoa aob aom aoo aor ar- ara arb arm aro arr arz az- aza azb azm azo azz baa bab bam bao bar baz bba bbb bbm bbo bbr bma bmb bmm bmo bmr bmz boa bob bom boo bor boz bra brb brm bro brr brz bza bzo bzr bzz m-o m-r maa mab mam mao mar maz mba mbb mbm mbo mbr mma mmb mmm mmo mmr mmz moa mob mom moo mor moz mra mrb mrm mro mrr mrz mza mzb mzm oaa oab oam oao oar ob- oba obb obm obo obr om- oma omb omm omo omr omz oo- ooa oob oom ooo oor or- ora orb orm oro orr orz oza ozm ozo ozz ra- raa rab ram rao rar raz rba rbb rbm rbo rbr rma rmb rmm rmo rmr roa rob rom roo ror roz rra rrb rrm rrr rza rzb rzm rzo zaa zab zam zao zar zaz zbb zbm zbr zma zmb zmm zo- zoa zob zom zoo zor zro zzr zzz