peb pec pee pek pel pen peo pep per pes pka pkb pkc pke pkl pkn pko pkp pkr pks pla plb plc ple plk pll pln plo plp plr pls pn- pna pnb pnc pne pnk pnl pnn pno pnp pnr pns poa pob poc poe pok pol pon poo pop por pos ppa ppb ppc ppe ppk ppl ppn ppo ppp ppr pps pra prb prc pre prk prl prn pro prp prr prs ps- psa psb psc pse psk psl psn pso psp psr pss ra- raa rab rac rae rak ral ran rao rap rar ras rba rbb rbc rbe rbk rbl rbn rbo rbp rbr rbs rca rcb rcc rce rcl rcn rco rcp rcr rcs re- rea reb rec ree rek rel ren reo rep rer res rkb rkc rke rkk rko rkp rks rla rlc rle rll rln rlo rlp rlr rls rna rnb rnc rnn rno rnp rnr rns roa rob roc roe rok rol ron roo rop ror ros rpa rpb rpc rpe rpk rpl rpn rpo rpp rpr rps rra rrb rrc rrk rrl rrn rrp rrr rrs rsa rsb rsc rse rsk rsl rsn rso rsp rsr rss saa sab sac sae sak sal san sao sap sar sas sba sbb sbc sbe sbk sbl sbn sbo sbp sbr sbs sca scb scc sce sck scl scn sco scp scr scs se- sea seb sec see sek sel sen seo sep ser ses sk- ska skb skc ske skk skl sko skp skr sks sla slb slc sle slk sll sln slo slp slr sls sna snb snc sne snk snl snn sno snp snr sns soa sob soc soe sok sol son soo sop sor sos spa spb spc spe spk spl spn spo spp spr sps sr- sra srb src sre srk srl srn sro srp srr srs ss- ssa ssb ssc sse ssk ssl ssn sso ssp ssr sss