a-a a-b a-c aaa aab aac aam aao aar aas aau ab- aba abb abc abm abo abr abs abu ac- aca acb acc acm aco acr acs acu ama amb amc amm amo amr ams amu aoa aob aoc aom aoo aor aos aou ar- ara arb arc arm aro arr ars aru as- asa asb asc asm aso asr ass asu au- aua aub auc aum auo aur aus b-u baa bab bac bam bao bar bas bau bba bbb bbc bbm bbo bbr bbs bbu bca bcb bcc bcm bco bcr bcs bcu bma bmb bmc bmm bmo bmr bms bmu boa bob boc bom boo bor bos bou bra brb brm bro brr brs bru bsa bsb bsc bsm bso bsr bss bsu bua bub buc bum buo bur bus buu c-- caa cab cac cam cao car cas cau cba cbb cbc cbm cbo cbr cbs cbu cca ccb ccc ccm cco ccr ccs ccu cma cmb cmc cmm cmo cmr cms cmu co- coa cob coc com coo cor cos cou cra crb crc crm cro crr crs cru csa csb csc csm cso csr css csu cua cub cuc cum cuo cur cus cuu m-o m-r maa mab mac mam mao mar mas mau mba mbb mbc mbm mbo mbr mbs mbu mc- mca mcb mcc mcm mco mcr mcs mcu mma mmb mmc mmm mmo mmr mms mmu moa mob moc mom moo mor mos mou mra mrb mrc mrm mro mrr mrs mru msa msb msc msm mso msr mss msu mua mub muc mum mur mus muu oaa oab oac oam oao oar oas oau ob- oba obb obc obm obo obr obs obu oc- oca ocb occ ocm oco ocr ocs ocu om- oma omb omc omm omo omr oms omu oo- ooa oob ooc oom ooo oor oos or- ora orb orc orm oro orr ors oru os- osa osb osc osm oso osr oss osu ou- oua ouc oum ouo our ous ra- raa rab rac ram rao rar ras rau rba rbb rbc rbm rbo rbr rbs rbu rca rcb rcc rcm rco rcr rcs rcu rma rmb rmc rmm rmo rmr rms roa rob roc rom roo ror ros rou rra rrb rrc rrm rrr rrs rru rsa rsb rsc rsm rso rsr rss rsu rua rub ruc rum ruo rur rus ruu saa sab sac sam sao sar sas sau sba sbb sbc sbm sbo sbr sbs sbu sca scb scc scm sco scr scs scu sma smb smc smm smo smr sms smu soa sob soc som soo sor sos sou sr- sra srb src srm sro srr srs ss- ssa ssb ssc ssm sso ssr sss ssu sua sub suc sum suo sur sus suu ua- uaa uab uac uam uao uar uas uau uba ubb ubc ubo ubr ubs ubu uca ucb ucc ucm uco ucr ucs ucu um- uma umb umc umm umo umr ums umu uoa uob uoc uom uoo uor uos ur- ura urb urc urm uro urr urs uru usa usb usc usm uso usr uss usu uua uuc uum uur uus uuu