-er -th bbb bbc bbe bbh bbk bbo bbr bbs bbt bcb bcc bce bch bck bco bcr bcs bct be- beb bec bee beh bek beo ber bes bet bhb bhc bhe bhh bhk bho bhr bhs bht bkb bkc bke bkk bko bkr bks bkt bob boc boe boh bok boo bor bos bot brb bre brh brk bro brr brs brt bsb bsc bse bsh bsk bso bsr bss bst btb btc bte bth btk bto btr bts btt c-- cbb cbc cbe cbh cbk cbo cbr cbs cbt ccb ccc cce cch cck cco ccr ccs cct ce- ceb cec cee ceh cek ceo cer ces cet ch- chb chc che chh chk cho chr chs cht ckb ckc ckh cko cks ckt co- cob coc coe coh cok coo cor cos cot crb crc cre crh crk cro crr crs crt csb csc cse csh csk cso csr css cst ctb ctc cte cth ctk cto ctr cts ctt ebb ebc ebe ebh ebk ebo ebr ebs ebt ec- ecb ecc ece ech eck eco ecr ecs ect eeb eec eee eek eeo eer ees eet ehb ehc ehe ehh eho ehr ehs eht ekb ekc eke ekh eko ekr eks ekt eo- eob eoc eoe eoh eok eoo eor eos eot erb erc ere erh erk ero err ers ert es- esb esc ese esh esk eso esr ess est etb etc ete eth etk eto etr ets ett hbb hbc hbe hbh hbk hbo hbr hbs hbt hcb hcc hce hch hck hco hcr hcs hct he- heb hec hee heh hek heo her hes het hhb hhc hhe hhh hhk hho hhr hhs hht hkb hkh hkk hko hkr hks hkt hob hoc hoe hoh hok hoo hor hos hot hr- hrb hrc hre hrh hrk hro hrr hrs hrt hsb hsc hse hsh hsk hsr hss hst htb htc hte hth htk hto htr hts htt k-t kbb kbc kbe kbh kbk kbo kbr kbs kcb kcc kce kch kck kcr kcs kct ke- keb kec kee keh kek keo ker kes ket khe khh khk kho khr khs kkb kkc kke kkh kkk kkr kks kkt kob koc koe koh kok koo kor kos kot krc krk kro krr krs krt ksb ksc kse ksh ksk kso ksr kss kst ktb ktc kte kth ktk kto ktr kts ktt ob- obb obc obe obh obk obo obr obs obt oc- ocb occ och ock oco ocr ocs oct oeb oec oee oeh oeo oer oes oet ohc ohe ohh oho ohr ohs oht okb okc oke okk oko okr oks oo- oob ooc ooh ook ooo oor oos oot or- orb orc ore orh ork oro orr ors ort os- osb osc ose osh osk oso osr oss ost ot- otb otc ote oth otk oto otr ots ott rbb rbc rbe rbh rbk rbo rbr rbs rbt rcb rcc rce rch rco rcr rcs rct re- reb rec ree reh rek reo rer res ret rh- rhb rhc rhe rhh rho rhr rhs rht rkb rkc rke rkk rko rks rkt rob roc roe roh rok roo ror ros rot rrb rrc rrh rrk rrr rrs rrt rsb rsc rse rsh rsk rso rsr rss rst rtb rtc rte rtk rto rtr rts rtt sbb sbc sbe sbh sbk sbo sbr sbs sbt scb scc sce sch sck sco scr scs sct se- seb sec see seh sek seo ser ses set sh- shb shc she shh shk sho shr shs sht sk- skb skc ske skh skk sko skr sks skt sob soc soe soh sok soo sor sos sot sr- srb src sre srh srk sro srr srs srt ss- ssb ssc sse ssh ssk sso ssr sss sst stb stc ste sth stk sto str sts stt tbb tbc tbe tbh tbk tbo tbr tbs tbt tcb tcc tce tch tck tco tcr tcs tct te- teb tec tee teh tek teo ter tes tet th- thb thc the thh thk tho thr ths tht tkb tkc tke tkk tko tkr tks tkt to- tob toc toe toh tok too tor tos tot trb trc tre trh trk tro trr trs trt tsb tsc tse tsh tsk tso tsr tss tst ttb ttc tte tth ttk tto ttr tts ttt