a-a a-b a-c aaa aab aac aad aao aar aau aay ab- aba abb abc abd abo abr abu aby ac- aca acb acc acd aco acr acu acy ad- ada adb adc add ado adr adu ady aoa aob aoc aod aoo aor aou ar- ara arb arc ard aro arr aru ary au- aua aub auc aud auo aur ay- aya ayc ayd ayo ayr ayu b-u baa bab bac bad bao bar bau bay bba bbb bbc bbd bbo bbr bbu bby bca bcb bcc bcd bco bcr bcu bcy bda bdb bdc bdd bdo bdr bdu bdy boa bob boc bod boo bor bou boy bra brb brd bro brr bru bry bua bub buc bud buo bur buu buy by- bya byc byd byo byr byu c-- caa cab cac cad cao car cau cay cba cbb cbc cbd cbo cbr cbu cby cca ccb ccc ccd cco ccr ccu cda cdb cdc cdd cdo cdr cdu cdy co- coa cob coc cod coo cor cou coy cra crb crc crd cro crr cru cry cua cub cuc cud cuo cur cuu cuy cya cyb cyc cyd cyo cyr daa dab dac dad dao dar dau day dba dbb dbc dbd dbo dbr dbu dby dca dcb dcc dcd dco dcr dcu dda ddb ddc ddd ddo ddr ddu ddy doa dob doc dod doo dor dou doy dra drb drc drd dro drr dru dry dua dub duc dud duo dur duy dy- dya dyb dyc dyd dyo dyr dyu dyy oaa oab oac oad oao oar oau ob- oba obb obc obd obo obr obu oby oc- oca ocb occ ocd oco ocr ocu oda odb odc odd odo odr odu oo- ooa oob ooc ood ooo oor or- ora orb orc ord oro orr oru ory ou- oua ouc oud ouo our oya oyd oyo ra- raa rab rac rad rao rar rau ray rba rbb rbc rbd rbo rbr rbu rca rcb rcc rcd rco rcr rcu rda rdb rdc rdd rdo rdr rdu rdy roa rob roc rod roo ror rou roy rra rrb rrc rrd rrr rru rua rub ruc rud ruo rur ruu ruy ry- rya ryc ryd ryo ryr ryu ryy ua- uaa uab uac uad uao uar uau uay uba ubb ubc ubo ubr ubu uby uca ucb ucc ucd uco ucr ucu uda udb udc udd udo udr udu uoa uob uoc uod uoo uor ur- ura urb urc urd uro urr uru ury uua uuc uur uuu uyc uyo uyu yaa yab yac yad yao yar yau yay ybc ybr yby yca ycc ycd yco ycu ycy yda ydo ydy yob yoc yod yoo yor you yoy yra yrc yro yru yua yud yuo yur yuu yuy yyb yyc yyu yyy