-ic bbb bbc bbi bbk bbn bbo bbt bcb bcc bci bck bcn bco bct bi- bib bic bii bik bin bio bit bkb bkc bkk bkn bko bkt bnb bnc bni bnk bnn bno bnt bob boc boi bok bon boo bot btb btc bti btk btn bto btt c-- cbb cbc cbi cbk cbn cbo cbt ccb ccc cci cck ccn cco cct ci- cib cic cii cik cin cio cit ckb ckc cki cko ckt cn- cnb cnc cni cnn cno cnt co- cob coc coi cok con coo cot ctb ctc cti ctk ctn cto ctt ibb ibc ibi ibk ibn ibo ibt icb icc ici ick icn ico ict iib iic iii iin iio iit ikb ikc iki ikk iko ikt in- inb inc ini ink inn ino int io- iob ioc ioi ion ioo iot itb itc iti itk itn ito itt k-t kbb kbc kbi kbk kbn kbo kcb kcc kci kck kcn kct kib kic kii kik kin kio kit kkb kkc kki kkk kkn kkt kn- knc kni knk knn kno knt kob koc koi kok kon koo kot ktb ktc ktk ktn kto ktt n-i nbb nbc nbi nbk nbn nbo nbt ncb ncc nci nck ncn nco nct nib nic nii nik nin nio nit nkc nki nkk nkn nko nkt nnb nnc nni nnk nnn nno nnt no- nob noc noi nok non noo not ntb ntc nti ntk ntn nto ntt o-i ob- obb obc obi obk obn obo obt oc- ocb occ oci ock ocn oco oct oib oic oii oik oin oio oit okb okc oki okk oko on- onb onc oni onk onn ono ont oo- oob ooc ooi ook oon ooo oot ot- otb otc oti otk otn oto ott tbb tbc tbi tbk tbn tbo tbt tcb tcc tci tck tcn tco tct tib tic tii tik tin tio tit tkb tkc tkk tko tkt tnb tnc tni tnk tnn tno tnt to- tob toc toi tok ton too tot ttb ttc tti ttk ttn tto ttt