-al -ol a-a a-b aaa aab aak aal aao aar ab- aba abb abk abl abo abr aka akb akk akl ako akr al- ala alb alk all alo alr aoa aob aok aol aoo aor ar- ara arb ark arl aro arr baa bab bak bal bao bar bba bbb bbk bbl bbo bbr bka bkb bkk bkl bko bkr bla blb blk bll blo blr boa bob bok bol boo bor bra brb brk brl bro brr ka- kaa kab kak kal kao kar kba kbb kbk kbl kbo kbr kkb kkk kkl kkr kl- kla klb klo klr koa kob kok kol koo kor kra krk krl kro krr la- laa lab lak lal lao lar lba lbb lbk lbl lbo lbr lka lkb lkl lkr lla llb llk lll llo llr loa lob lok lol loo lor lra lrb lrk lro lrr oaa oab oak oal oao oar ob- oba obb obk obl obo obr oka okb okk okl oko okr ola olb olk oll olo oo- ooa oob ook ool ooo oor or- ora orb ork orl oro orr ra- raa rab rak ral rao rar rba rbb rbk rbl rbo rbr rkb rkk rko rla rll rlo rlr roa rob rok rol roo ror rra rrb rrk rrl rrr