bbb bbc bbd bbe bbk bbo bbs bcb bcc bcd bce bck bco bcs bdb bdc bdd bde bdk bdo bds be- beb bec bed bee bek beo bes bkb bkc bke bkk bko bks bob boc bod boe bok boo bos bsb bsc bsd bse bsk bso bss c-- cbb cbc cbd cbe cbk cbo cbs ccb ccc ccd cce cck cco ccs cdb cdc cdd cde cdk cdo cds ce- ceb cec ced cee cek ceo ces ckb ckc ckd cko cks co- cob coc cod coe cok coo cos csb csc csd cse csk cso css dbb dbc dbd dbe dbk dbo dbs dcb dcc dcd dce dck dco dcs ddb ddc ddd dde ddk ddo dds de- deb dec ded dee dek deo des dkb dkc dke dkk dko dks dob doc dod doe dok doo dos dsb dsc dsd dse dsk dso dss ebb ebc ebd ebe ebk ebo ebs ec- ecb ecc ecd ece eck eco ecs ed- edb edc edd ede edk edo eds eeb eec eed eee eek eeo ees ekb ekc ekd eke eko eks eo- eob eoc eod eoe eok eoo eos es- esb esc esd ese esk eso ess kbb kbc kbd kbe kbk kbo kbs kcb kcc kcd kce kck kcs kdb kdc kde kdk kdo kds ke- keb kec ked kee kek keo kes kkb kkc kke kkk kks kob koc kod koe kok koo kos ksb ksc ksd kse ksk kso kss ob- obb obc obd obe obk obo obs oc- ocb occ ocd ock oco ocs odb odc odd ode odo ods oeb oec oed oee oeo oes okb okc okd oke okk oko oks oo- oob ooc ood ook ooo oos os- osb osc osd ose osk oso oss sbb sbc sbd sbe sbk sbo sbs scb scc scd sce sck sco scs sdb sdc sdd sde sdk sdo sds se- seb sec sed see sek seo ses sk- skb skc skd ske skk sko sks sob soc sod soe sok soo sos ss- ssb ssc ssd sse ssk sso sss