-al -ol a-a a-b a-c a-t aaa aab aac aak aal aao aas aat ab- aba abb abc abk abl abo abs abt ac- aca acb acc ack acl aco acs act aka akb akc akk akl ako aks al- ala alb alc alk all alo als alt aoa aob aoc aok aol aoo aos aot as- asa asb asc ask asl aso ass ast at- ata atb atc atl ato ats att baa bab bac bak bal bao bas bat bba bbb bbc bbk bbl bbo bbs bbt bca bcb bcc bck bcl bco bcs bct bka bkb bkc bkk bkl bko bks bkt bla blb blc blk bll blo bls blt boa bob boc bok bol boo bos bot bsa bsb bsc bsk bsl bso bss bst bta btb btc btk btl bto bts btt c-- caa cab cac cak cal cao cas cat cba cbb cbc cbk cbl cbo cbs cbt cca ccb ccc cck ccl cco ccs cct cka ckb ckc cko cks ckt cl- cla clb clc clk cll clo cls clt co- coa cob coc cok col coo cos cot csa csb csc csk csl cso css cst cta ctb ctc ctk ctl cto cts ctt k-t ka- kaa kab kac kak kal kao kas kat kba kbb kbc kbk kbl kbo kbs kca kcb kcc kck kcl kcs kct kkb kkc kkk kkl kks kkt kl- kla klb klc klo kls klt koa kob koc kok kol koo kos kot ksa ksb ksc ksk ksl kso kss kst kta ktb ktc ktk ktl kto kts ktt la- laa lab lac lak lal lao las lat lba lbb lbc lbk lbl lbo lbs lbt lca lcb lcc lck lcl lco lcs lct lka lkb lkl lks lkt lla llb llc llk lll llo lls llt loa lob loc lok lol loo los lot lsa lsb lsc lsk lsl lso lss lst lta ltb ltc ltk ltl lto lts ltt oaa oab oac oak oal oao oas oat ob- oba obb obc obk obl obo obs obt oc- oca ocb occ ock ocl oco ocs oct oka okb okc okk okl oko oks ola olb olc olk oll olo ols olt oo- ooa oob ooc ook ool ooo oos oot os- osa osb osc osk osl oso oss ost ot- ota otb otc otk otl oto ots ott saa sab sac sak sal sao sas sat sba sbb sbc sbk sbl sbo sbs sbt sca scb scc sck scl sco scs sct sk- ska skb skc skk skl sko sks skt sla slb slc slk sll slo sls slt soa sob soc sok sol soo sos sot ss- ssa ssb ssc ssk ssl sso sss sst sta stb stc stk stl sto sts stt taa tab tac tak tal tao tas tat tba tbb tbc tbk tbl tbo tbs tbt tca tcb tcc tck tcl tco tcs tct tka tkb tkc tkk tkl tko tks tkt tla tlc tlk tll tlo tls tlt to- toa tob toc tok tol too tos tot tsa tsb tsc tsk tsl tso tss tst tta ttb ttc ttk ttl tto tts ttt