-er b-p bbb bbc bbe bbk bbn bbp bbr bcb bcc bce bck bcn bcp bcr be- beb bec bee bek ben bep ber bkb bkc bke bkk bkn bkp bkr bnb bnc bne bnk bnn bnp bnr bpb bpc bpe bpn bpp bpr brb bre brk brn brp brr c-- cbb cbc cbe cbk cbn cbp cbr ccb ccc cce cck ccn ccp ccr ce- ceb cec cee cek cen cep cer ckb ckc cn- cnb cnc cne cnn cnp cnr cpb cpc cpe cpk cpn cpp cpr crb crc cre crk crn crp crr ebb ebc ebe ebk ebn ebp ebr ec- ecb ecc ece eck ecn ecr eeb eec eee eek een eep eer ekb ekc eke ekp ekr en- enb enc ene enk enn enp enr ep- epb epc epe epn epp epr erb erc ere erk ern erp err kbb kbc kbe kbk kbn kbp kbr kcb kcc kce kck kcn kcp kcr ke- keb kec kee kek ken kep ker kkb kkc kke kkk kkn kkp kkr kn- knc kne knk knn knp knr kpc kpe kpk kpn kpp kpr krc krk krn krp krr nbb nbc nbe nbk nbn nbp nbr ncb ncc nce nck ncn ncp ncr ne- neb nec nee nek nen nep ner nkc nke nkk nkn nkp nkr nnb nnc nne nnk nnn nnp npb npc npe npn npp npr nrb nrc nre nrk nrn nrp nrr p-p pbb pbc pbe pbk pbn pbp pbr pcb pcc pce pck pcn pcp pcr peb pec pee pek pen pep per pkb pkc pke pkn pkp pkr pn- pnb pnc pne pnk pnn pnp pnr ppb ppc ppe ppk ppn ppp ppr prb prc pre prk prn prp prr rbb rbc rbe rbk rbn rbp rbr rcb rcc rce rcn rcp rcr re- reb rec ree rek ren rep rer rkb rkc rke rkk rkp rnb rnc rnn rnp rnr rpb rpc rpe rpk rpn rpp rpr rrb rrc rrk rrn rrp rrr