o-i oaa oab oac oad oae oai oam oan oao oar oas ob- oba obb obc obd obe obi obm obn obo obr obs oc- oca ocb occ ocd oci ocm ocn oco ocr ocs oda odb odc odd ode odi odm odn odo odr ods oea oeb oec oed oee oei oem oen oeo oer oes oia oib oic oid oie oii oim oin oio oir ois om- oma omb omc omd ome omi omm omn omo omr oms on- ona onb onc ond one oni onn ono onr ons oo- ooa oob ooc ood ooi oom oon ooo oor oos or- ora orb orc ord ore ori orm orn oro orr ors os- osa osb osc osd ose osi osm osn oso osr oss ra- raa rab rac rad rae rai ram ran rao rar ras rba rbb rbc rbd rbe rbi rbm rbn rbo rbr rbs rca rcb rcc rcd rce rci rcm rcn rco rcr rcs rda rdb rdc rdd rde rdi rdm rdn rdo rdr rds re- rea reb rec red ree rei rem ren reo rer res ria rib ric rid rie rii rim rin rio rir ris rma rmb rmc rmd rme rmi rmm rmn rmo rmr rms rna rnb rnc rnd rni rnm rnn rno rnr rns roa rob roc rod roe roi rom ron roo ror ros rra rrb rrc rrd rri rrm rrn rrr rrs rsa rsb rsc rsd rse rsi rsm rsn rso rsr rss saa sab sac sad sae sai sam san sao sar sas sba sbb sbc sbd sbe sbi sbm sbn sbo sbr sbs sca scb scc scd sce sci scm scn sco scr scs sda sdb sdc sdd sde sdi sdm sdn sdo sdr sds se- sea seb sec sed see sei sem sen seo ser ses sia sib sic sid sie sii sim sin sio sir sis sma smb smc smd sme smi smm smn smo smr sms sna snb snc snd sne sni snm snn sno snr sns soa sob soc sod soe soi som son soo sor sos sr- sra srb src srd sre sri srm srn sro srr srs ss- ssa ssb ssc ssd sse ssi ssm ssn sso ssr sss