-ic bbb bbc bbd bbi bbo bbs bbt bcb bcc bcd bci bco bcs bct bdb bdc bdd bdi bdo bds bdt bi- bib bic bid bii bio bis bit bob boc bod boi boo bos bot bsb bsc bsd bsi bso bss bst btb btc btd bti bto bts btt c-- cbb cbc cbd cbi cbo cbs cbt ccb ccc ccd cci cco ccs cct cdb cdc cdd cdi cdo cds cdt ci- cib cic cid cii cio cis cit co- cob coc cod coi coo cos cot csb csc csd csi cso css cst ctb ctc ctd cti cto cts ctt dbb dbc dbd dbi dbo dbs dbt dcb dcc dcd dci dco dcs dct ddb ddc ddd ddi ddo dds ddt di- dib dic did dii dio dis dit dob doc dod doi doo dos dot dsb dsc dsd dsi dso dss dst dtb dtc dtd dti dto dts dtt i-d ibb ibc ibd ibi ibo ibs ibt icb icc icd ici ico ics ict idb idc idd idi ido ids idt iib iic iid iii iio iis iit io- iob ioc iod ioi ioo ios iot is- isb isc isd isi iso iss ist itb itc itd iti ito its itt o-i ob- obb obc obd obi obo obs obt oc- ocb occ ocd oci oco ocs oct odb odc odd odi odo ods odt oib oic oid oii oio ois oit oo- oob ooc ood ooi ooo oos oot os- osb osc osd osi oso oss ost ot- otb otc otd oti oto ots ott sbb sbc sbd sbi sbo sbs sbt scb scc scd sci sco scs sct sdb sdc sdd sdi sdo sds sdt sib sic sid sii sio sis sit sob soc sod soi soo sos sot ss- ssb ssc ssd ssi sso sss sst stb stc std sti sto sts stt tbb tbc tbd tbi tbo tbs tbt tcb tcc tcd tci tco tcs tct tdb tdc tdd tdi tdo tds tdt tib tic tid tii tio tis tit to- tob toc tod toi too tos tot tsb tsc tsd tsi tso tss tst ttb ttc ttd tti tto tts ttt