-er b-p bbb bbe bbn bbo bbp bbr bbt be- beb bee ben beo bep ber bet bnb bne bnn bno bnp bnr bnt bob boe bon boo bop bor bot bpb bpe bpn bpo bpp bpr bpt brb bre brn bro brp brr brt btb bte btn bto btp btr btt ebb ebe ebn ebo ebp ebr ebt eeb eee een eeo eep eer eet en- enb ene enn eno enp enr ent eo- eob eoe eon eoo eop eor eot ep- epb epe epn epo epp epr ept erb ere ern ero erp err ert etb ete etn eto etp etr ett nbb nbe nbn nbo nbp nbr nbt ne- neb nee nen neo nep ner net nnb nne nnn nno nnp nnt no- nob noe non noo nop nor not npb npe npn npo npp npr npt nrb nre nrn nro nrp nrr nrt ntb nte ntn nto ntp ntr ntt ob- obb obe obn obo obp obr obt oeb oee oen oeo oep oer oet on- onb one onn ono onp onr ont oo- oob oon ooo oop oor oot op- opb ope opn opo opp opr opt or- orb ore orn oro orp orr ort ot- otb ote otn oto otp otr ott p-p pbb pbe pbn pbo pbp pbr pbt peb pee pen peo pep per pet pn- pnb pne pnn pno pnp pnr pnt pob poe pon poo pop por pot ppb ppe ppn ppo ppp ppr ppt prb pre prn pro prp prr prt pt- ptb pte ptn pto ptp ptr ptt rbb rbe rbn rbo rbp rbr rbt re- reb ree ren reo rep rer ret rnb rnn rno rnp rnr rnt rob roe ron roo rop ror rot rpb rpe rpn rpo rpp rpr rpt rrb rrn rrp rrr rrt rtb rte rtn rto rtp rtr rtt tbb tbe tbn tbo tbp tbr tbt te- teb tee ten teo tep ter tet tnb tne tnn tno tnp tnr tnt to- tob toe ton too top tor tot tpb tpe tpn tpo tpp tpr tpt trb tre trn tro trp trr trt ttb tte ttn tto ttp ttr ttt