-er -ol b-p bbb bbc bbe bbk bbl bbo bbp bbr bcb bcc bce bck bcl bco bcp bcr be- beb bec bee bek bel beo bep ber bkb bkc bke bkk bkl bko bkp bkr blb blc ble blk bll blo blp blr bob boc boe bok bol boo bop bor bpb bpc bpe bpl bpo bpp bpr brb bre brk brl bro brp brr c-- cbb cbc cbe cbk cbl cbo cbp cbr ccb ccc cce cck ccl cco ccp ccr ce- ceb cec cee cek cel ceo cep cer ckb ckc cko cl- clb clc cle clk cll clo clp clr co- cob coc coe cok col coo cop cor cpb cpc cpe cpk cpl cpo cpp cpr crb crc cre crk crl cro crp crr ebb ebc ebe ebk ebl ebo ebp ebr ec- ecb ecc ece eck ecl eco ecr eeb eec eee eek eel eeo eep eer ekb ekc eke ekl eko ekp ekr elb elc ele elk ell elo elp elr eo- eob eoc eoe eok eol eoo eop eor ep- epb epc epe epl epo epp epr erb erc ere erk erl ero erp err kbb kbc kbe kbk kbl kbo kbp kbr kcb kcc kce kck kcl kcp kcr ke- keb kec kee kek kel keo kep ker kkb kkc kke kkk kkl kkp kkr kl- klb klc klo klr kob koc koe kok kol koo kop kor kpc kpe kpk kpl kpo kpp kpr krc krk krl kro krp krr l-p lbb lbc lbe lbk lbl lbo lbp lbr lcb lcc lce lck lcl lco lcp lcr leb lec lee lek lel leo lep ler lkb lkl lkp lkr llb llc lle llk lll llo llp llr lob loc loe lok lol loo lop lor lpb lpc lpe lpk lpl lpo lpp lpr lrb lrc lrk lro lrp lrr ob- obb obc obe obk obl obo obp obr oc- ocb occ ock ocl oco ocp ocr oeb oec oee oel oeo oep oer okb okc oke okk okl oko okp okr olb olc ole olk oll olo olp oo- oob ooc ook ool ooo oop oor op- opb opc ope opk opl opo opp opr or- orb orc ore ork orl oro orp orr p-p pbb pbc pbe pbk pbl pbo pbp pbr pcb pcc pce pck pcl pco pcp pcr peb pec pee pek pel peo pep per pkb pkc pke pkl pko pkp pkr plb plc ple plk pll plo plp plr pob poc poe pok pol poo pop por ppb ppc ppe ppk ppl ppo ppp ppr prb prc pre prk prl pro prp prr rbb rbc rbe rbk rbl rbo rbp rbr rcb rcc rce rcl rco rcp rcr re- reb rec ree rek rel reo rep rer rkb rkc rke rkk rko rkp rlc rle rll rlo rlp rlr rob roc roe rok rol roo rop ror rpb rpc rpe rpk rpl rpo rpp rpr rrb rrc rrk rrl rrp rrr