a-a a-b aaa aab aad aao aar aay ab- aba abb abd abo abr aby ad- ada adb add ado adr ady aoa aob aod aoo aor ar- ara arb ard aro arr ary ay- aya ayd ayo ayr baa bab bad bao bar bay bba bbb bbd bbo bbr bby bda bdb bdd bdo bdr bdy boa bob bod boo bor boy bra brb brd bro brr bry by- bya byd byo byr daa dab dad dao dar day dba dbb dbd dbo dbr dby dda ddb ddd ddo ddr ddy doa dob dod doo dor doy dra drb drd dro drr dry dy- dya dyb dyd dyo dyr dyy oaa oab oad oao oar ob- oba obb obd obo obr oby oda odb odd odo odr oo- ooa oob ood ooo oor or- ora orb ord oro orr ory oya oyd oyo ra- raa rab rad rao rar ray rba rbb rbd rbo rbr rda rdb rdd rdo rdr rdy roa rob rod roo ror roy rra rrb rrd rrr ry- rya ryd ryo ryr ryy yaa yab yad yao yar yay ybr yby yda ydo ydy yob yod yoo yor yoy yra yro yyb yyy