-er bbb bbc bbd bbe bbh bbk bbo bbr bcb bcc bcd bce bch bck bco bcr bdb bdc bdd bde bdh bdk bdo bdr be- beb bec bed bee beh bek beo ber bhb bhc bhd bhe bhh bhk bho bhr bkb bkc bke bkk bko bkr bob boc bod boe boh bok boo bor brb brd bre brh brk bro brr c-- cbb cbc cbd cbe cbh cbk cbo cbr ccb ccc ccd cce cch cck cco ccr cdb cdc cdd cde cdh cdk cdo cdr ce- ceb cec ced cee ceh cek ceo cer ch- chb chc chd che chh chk cho chr ckb ckc ckd ckh cko co- cob coc cod coe coh cok coo cor crb crc crd cre crh crk cro crr dbb dbc dbd dbe dbh dbk dbo dbr dcb dcc dcd dce dck dco dcr ddb ddc ddd dde ddh ddk ddo ddr de- deb dec ded dee deh dek deo der dh- dhb dhc dhd dhe dhh dhk dho dhr dkb dkc dke dkk dko dkr dob doc dod doe doh dok doo dor drb drc drd dre drk dro drr ebb ebc ebd ebe ebh ebk ebo ebr ec- ecb ecc ecd ece ech eck eco ecr ed- edb edc edd ede edh edk edo edr eeb eec eed eee eek eeo eer ehb ehc ehd ehe ehh eho ehr ekb ekc ekd eke ekh eko ekr eo- eob eoc eod eoe eoh eok eoo eor erb erc erd ere erh erk ero err hbb hbc hbd hbe hbh hbk hbo hbr hcb hcc hcd hce hch hck hco hcr hdb hdc hdd hde hdh hdk hdo hdr he- heb hec hed hee heh hek heo her hhb hhc hhd hhe hhh hhk hho hhr hkb hkd hkh hkk hko hkr hob hoc hod hoe hoh hok hoo hor hr- hrb hrc hrd hre hrh hrk hro hrr kbb kbc kbd kbe kbh kbk kbo kbr kcb kcc kcd kce kch kck kcr kdb kdc kde kdh kdk kdo kdr ke- keb kec ked kee keh kek keo ker khe khh khk kho khr kkb kkc kke kkh kkk kkr kob koc kod koe koh kok koo kor krc krd krk kro krr ob- obb obc obd obe obh obk obo obr oc- ocb occ ocd och ock oco ocr odb odc odd ode odh odo odr oeb oec oed oee oeh oeo oer ohc ohd ohe ohh oho ohr okb okc okd oke okk oko okr oo- oob ooc ood ooh ook ooo oor or- orb orc ord ore orh ork oro orr rbb rbc rbd rbe rbh rbk rbo rbr rcb rcc rcd rce rch rco rcr rdb rdc rdd rde rdh rdo rdr re- reb rec red ree reh rek reo rer rh- rhb rhc rhd rhe rhh rho rhr rkb rkc rke rkk rko rob roc rod roe roh rok roo ror rrb rrc rrd rrh rrk rrr