-al -ol a-a a-b a-c a-t aaa aab aac aal aao aat aax ab- aba abb abc abl abo abt abx ac- aca acb acc acl aco act acx al- ala alb alc all alo alt alx aoa aob aoc aol aoo aot aox at- ata atb atc atl ato att atx ax- axa axl axo axt axx baa bab bac bal bao bat bax bba bbb bbc bbl bbo bbt bbx bca bcb bcc bcl bco bct bcx bla blb blc bll blo blt blx boa bob boc bol boo bot box bta btb btc btl bto btt btx bxb bxl bxo bxx c-- caa cab cac cal cao cat cax cba cbb cbc cbl cbo cbt cbx cca ccb ccc ccl cco cct ccx cl- cla clb clc cll clo clt clx co- coa cob coc col coo cot cox cta ctb ctc ctl cto ctt ctx cxc cxl cxo cxt cxx la- laa lab lac lal lao lat lax lba lbb lbc lbl lbo lbt lbx lca lcb lcc lcl lco lct lcx lla llb llc lll llo llt loa lob loc lol loo lot lox lta ltb ltc ltl lto ltt ltx lxc lxo lxx oaa oab oac oal oao oat oax ob- oba obb obc obl obo obt obx oc- oca ocb occ ocl oco oct ocx ola olb olc oll olo olt oo- ooa oob ooc ool ooo oot oox ot- ota otb otc otl oto ott ox- oxa oxb oxc oxo oxt oxx t-x taa tab tac tal tao tat tax tba tbb tbc tbl tbo tbt tca tcb tcc tcl tco tct tcx tla tlc tll tlo tlt tlx to- toa tob toc tol too tot tox tta ttb ttc ttl tto ttt ttx txl txt xaa xac xal xat xbc xbl xbx xcb xcl xcx xla xlb xlt xoa xoc xoo xot xox xtc xtx xxl xxo xxx