-ic bbb bbc bbi bbo bbs bcb bcc bci bco bcs bi- bib bic bii bio bis bob boc boi boo bos bsb bsc bsi bso bss c-- cbb cbc cbi cbo cbs ccb ccc cci cco ccs ci- cib cic cii cio cis co- cob coc coi coo cos csb csc csi cso css ibb ibc ibi ibo ibs icb icc ici ico ics iib iic iii iio iis io- iob ioc ioi ioo ios is- isb isc isi iso iss o-i ob- obb obc obi obo obs oc- ocb occ oci oco ocs oib oic oii oio ois oo- oob ooc ooi ooo oos os- osb osc osi oso oss sbb sbc sbi sbo sbs scb scc sci sco scs sib sic sii sio sis sob soc soi soo sos ss- ssb ssc ssi sso sss