-ic a-a a-b a-c a-i a-t aaa aab aac aai aak aan aao aat ab- aba abb abc abi abk abn abo abt ac- aca acb acc aci ack acn aco act ai- aia aib aic aii aik ain aio ait aka akb akc aki akk akn ako an- ana anb anc ani ank ann ano ant aoa aob aoc aoi aok aon aoo aot at- ata atb atc ati atn ato att baa bab bac bai bak ban bao bat bba bbb bbc bbi bbk bbn bbo bbt bca bcb bcc bci bck bcn bco bct bi- bia bib bic bii bik bin bio bit bka bkb bkc bkk bkn bko bkt bna bnb bnc bni bnk bnn bno bnt boa bob boc boi bok bon boo bot bta btb btc bti btk btn bto btt c-- caa cab cac cai cak can cao cat cba cbb cbc cbi cbk cbn cbo cbt cca ccb ccc cci cck ccn cco cct ci- cia cib cic cii cik cin cio cit cka ckb ckc cki cko ckt cn- cna cnb cnc cni cnn cno cnt co- coa cob coc coi cok con coo cot cta ctb ctc cti ctk ctn cto ctt ia- iaa iab iac iai ian iao iat iba ibb ibc ibi ibk ibn ibo ibt ica icb icc ici ick icn ico ict iia iib iic iii iin iio iit ika ikb ikc iki ikk iko ikt in- ina inb inc ini ink inn ino int io- ioa iob ioc ioi ion ioo iot ita itb itc iti itk itn ito itt k-t ka- kaa kab kac kai kak kan kao kat kba kbb kbc kbi kbk kbn kbo kca kcb kcc kci kck kcn kct kia kib kic kii kik kin kio kit kkb kkc kki kkk kkn kkt kn- kna knc kni knk knn kno knt koa kob koc koi kok kon koo kot kta ktb ktc ktk ktn kto ktt n-i naa nab nac nai nak nan nao nat nba nbb nbc nbi nbk nbn nbo nbt nca ncb ncc nci nck ncn nco nct nia nib nic nii nik nin nio nit nka nkc nki nkk nkn nko nkt nna nnb nnc nni nnk nnn nno nnt no- noa nob noc noi nok non noo not nta ntb ntc nti ntk ntn nto ntt o-i oaa oab oac oai oak oan oao oat ob- oba obb obc obi obk obn obo obt oc- oca ocb occ oci ock ocn oco oct oia oib oic oii oik oin oio oit oka okb okc oki okk oko on- ona onb onc oni onk onn ono ont oo- ooa oob ooc ooi ook oon ooo oot ot- ota otb otc oti otk otn oto ott taa tab tac tai tak tan tao tat tba tbb tbc tbi tbk tbn tbo tbt tca tcb tcc tci tck tcn tco tct tia tib tic tii tik tin tio tit tka tkb tkc tkk tko tkt tna tnb tnc tni tnk tnn tno tnt to- toa tob toc toi tok ton too tot tta ttb ttc tti ttk ttn tto ttt