-er -up eee eef eep eer ees ef- efe eff efp efr efs ep- epe epf epp epr eps epu ere erf erp err ers eru es- ese esf esp esr ess esu eu- eue euf eup eur eus fee fef fep fer fes feu ffe fff ffp ffr ffs ffu fpe fpp fpr fps fpu fre frf frp frr frs fru fse fsf fsp fsr fss fsu fue fuf fup fur fus fuu p-p pee pef pep per pes peu pfe pff pfp pfr pfs pfu ppe ppf ppp ppr pps ppu pre prf prp prr prs pru ps- pse psf psp psr pss psu pue puf pup pur pus puu re- ree ref rep rer res reu rfe rff rfp rfr rfs rfu rpe rpf rpp rpr rps rpu rrf rrp rrr rrs rru rse rsf rsp rsr rss rsu rue ruf rup rur rus ruu se- see sef sep ser ses seu sfe sff sfp sfr sfs sfu spe spf spp spr sps spu sr- sre srf srp srr srs ss- sse ssf ssp ssr sss ssu sue suf sup sur sus suu uee uef uep uer ues ufe uff ufp ufr ufs ufu up- upe upf upp upr ups upu ur- ure urf urp urr urs uru use usf usp usr uss usu uue uur uus uuu