-al -ol a-a a-b aaa aab aal aao aar aax ab- aba abb abl abo abr abx al- ala alb all alo alr alx aoa aob aol aoo aor aox ar- ara arb arl aro arr arx ax- axa axl axo axr axx baa bab bal bao bar bax bba bbb bbl bbo bbr bbx bla blb bll blo blr blx boa bob bol boo bor box bra brb brl bro brr brx bxb bxl bxo bxx la- laa lab lal lao lar lax lba lbb lbl lbo lbr lbx lla llb lll llo llr loa lob lol loo lor lox lra lrb lro lrr lxo lxr lxx oaa oab oal oao oar oax ob- oba obb obl obo obr obx ola olb oll olo oo- ooa oob ool ooo oor oox or- ora orb orl oro orr orx ox- oxa oxb oxo oxx ra- raa rab ral rao rar rax rba rbb rbl rbo rbr rbx rla rll rlo rlr roa rob rol roo ror rox rra rrb rrl rrr rxr xaa xal xar xbl xbr xbx xla xlb xlr xoa xoo xor xox xrx xxl xxo xxx