-er c-- ccc cce ccg ccn cco ccp ccr ce- cec cee ceg cen ceo cep cer cgc cge cgg cgn cgo cgp cgr cn- cnc cne cng cnn cno cnp cnr co- coc coe cog con coo cop cor cpc cpe cpg cpn cpo cpp cpr crc cre crg crn cro crp crr ec- ecc ece ecg ecn eco ecr eec eee eeg een eeo eep eer egc ege egg egn ego egp egr en- enc ene eng enn eno enp enr eo- eoc eoe eog eon eoo eop eor ep- epc epe epg epn epo epp epr erc ere erg ern ero erp err g-p gcc gce gcg gcn gco gcp gcr ge- gec gee geg gen geo gep ger ggc ggg ggn ggo ggp ggr gnc gne gnn gno gnp gnr goc goe gog gon goo gop gor gpc gpe gpg gpn gpo gpp gpr grc gre grg grn gro grp grr ncc nce ncg ncn nco ncp ncr ne- nec nee neg nen neo nep ner ngc nge ngg ngn ngo ngp nnc nne nng nnn nno nnp no- noc noe nog non noo nop nor npc npe npg npn npo npp npr nrc nre nrg nrn nro nrp nrr oc- occ ocg ocn oco ocp ocr oec oee oeg oen oeo oep oer ogc oge ogg ogn ogo ogp on- onc one ong onn ono onp onr oo- ooc oog oon ooo oop oor op- opc ope opg opn opo opp opr or- orc ore org orn oro orp orr p-p pcc pce pcg pcn pco pcp pcr pec pee peg pen peo pep per pgc pge pgg pgn pgo pgp pgr pn- pnc pne png pnn pno pnp pnr poc poe pog pon poo pop por ppc ppe ppg ppn ppo ppp ppr prc pre prg prn pro prp prr rcc rce rcg rcn rco rcp rcr re- rec ree reg ren reo rep rer rgc rge rgg rgn rgo rgp rgr rnc rng rnn rno rnp rnr roc roe rog ron roo rop ror rpc rpe rpg rpn rpo rpp rpr rrc rrg rrn rrp rrr