-ic bbb bbc bbi bbn bbo bbs bbt bcb bcc bci bcn bco bcs bct bi- bib bic bii bin bio bis bit bnb bnc bni bnn bno bns bnt bob boc boi bon boo bos bot bsb bsc bsi bsn bso bss bst btb btc bti btn bto bts btt c-- cbb cbc cbi cbn cbo cbs cbt ccb ccc cci ccn cco ccs cct ci- cib cic cii cin cio cis cit cn- cnb cnc cni cnn cno cns cnt co- cob coc coi con coo cos cot csb csc csi csn cso css cst ctb ctc cti ctn cto cts ctt ibb ibc ibi ibn ibo ibs ibt icb icc ici icn ico ics ict iib iic iii iin iio iis iit in- inb inc ini inn ino ins int io- iob ioc ioi ion ioo ios iot is- isb isc isi isn iso iss ist itb itc iti itn ito its itt n-i nbb nbc nbi nbn nbo nbs nbt ncb ncc nci ncn nco ncs nct nib nic nii nin nio nis nit nnb nnc nni nnn nno nns nnt no- nob noc noi non noo nos not nsb nsc nsi nsn nso nss nst ntb ntc nti ntn nto nts ntt o-i ob- obb obc obi obn obo obs obt oc- ocb occ oci ocn oco ocs oct oib oic oii oin oio ois oit on- onb onc oni onn ono ons ont oo- oob ooc ooi oon ooo oos oot os- osb osc osi osn oso oss ost ot- otb otc oti otn oto ots ott sbb sbc sbi sbn sbo sbs sbt scb scc sci scn sco scs sct sib sic sii sin sio sis sit snb snc sni snn sno sns snt sob soc soi son soo sos sot ss- ssb ssc ssi ssn sso sss sst stb stc sti stn sto sts stt tbb tbc tbi tbn tbo tbs tbt tcb tcc tci tcn tco tcs tct tib tic tii tin tio tis tit tnb tnc tni tnn tno tns tnt to- tob toc toi ton too tos tot tsb tsc tsi tsn tso tss tst ttb ttc tti ttn tto tts ttt