-ic bbb bbc bbi bbk bbn bbo bbs bbt bcb bcc bci bck bcn bco bcs bct bi- bib bic bii bik bin bio bis bit bkb bkc bkk bkn bko bks bkt bnb bnc bni bnk bnn bno bns bnt bob boc boi bok bon boo bos bot bsb bsc bsi bsk bsn bso bss bst btb btc bti btk btn bto bts btt c-- cbb cbc cbi cbk cbn cbo cbs cbt ccb ccc cci cck ccn cco ccs cct ci- cib cic cii cik cin cio cis cit ckb ckc cki cko cks ckt cn- cnb cnc cni cnn cno cns cnt co- cob coc coi cok con coo cos cot csb csc csi csk csn cso css cst ctb ctc cti ctk ctn cto cts ctt ibb ibc ibi ibk ibn ibo ibs ibt icb icc ici ick icn ico ics ict iib iic iii iin iio iis iit ikb ikc iki ikk iko iks ikt in- inb inc ini ink inn ino ins int io- iob ioc ioi ion ioo ios iot is- isb isc isi isk isn iso iss ist itb itc iti itk itn ito its itt k-t kbb kbc kbi kbk kbn kbo kbs kcb kcc kci kck kcn kcs kct kib kic kii kik kin kio kis kit kkb kkc kki kkk kkn kks kkt kn- knc kni knk knn kno knt kob koc koi kok kon koo kos kot ksb ksc ksi ksk ksn kso kss kst ktb ktc ktk ktn kto kts ktt n-i nbb nbc nbi nbk nbn nbo nbs nbt ncb ncc nci nck ncn nco ncs nct nib nic nii nik nin nio nis nit nkc nki nkk nkn nko nks nkt nnb nnc nni nnk nnn nno nns nnt no- nob noc noi nok non noo nos not nsb nsc nsi nsk nsn nso nss nst ntb ntc nti ntk ntn nto nts ntt o-i ob- obb obc obi obk obn obo obs obt oc- ocb occ oci ock ocn oco ocs oct oib oic oii oik oin oio ois oit okb okc oki okk oko oks on- onb onc oni onk onn ono ons ont oo- oob ooc ooi ook oon ooo oos oot os- osb osc osi osk osn oso oss ost ot- otb otc oti otk otn oto ots ott sbb sbc sbi sbk sbn sbo sbs sbt scb scc sci sck scn sco scs sct sib sic sii sik sin sio sis sit sk- skb skc ski skk sko sks skt snb snc sni snk snn sno sns snt sob soc soi sok son soo sos sot ss- ssb ssc ssi ssk ssn sso sss sst stb stc sti stk stn sto sts stt tbb tbc tbi tbk tbn tbo tbs tbt tcb tcc tci tck tcn tco tcs tct tib tic tii tik tin tio tis tit tkb tkc tkk tko tks tkt tnb tnc tni tnk tnn tno tns tnt to- tob toc toi tok ton too tos tot tsb tsc tsi tsk tsn tso tss tst ttb ttc tti ttk ttn tto tts ttt