oo- ooo oop oor oos oot op- opo opp opq opr ops opt oqo or- oro orp orr ors ort os- oso osp osq osr oss ost ot- oto otp otr ots ott p-p poo pop por pos pot ppo ppp ppq ppr pps ppt pqq pqr pqs pro prp prq prr prs prt ps- pso psp psr pss pst pt- pto ptp ptq ptr pts ptt qoo qop qor qos qpp qpr qps qqq qrp qrs qrt qso qsp qsr qst qto qtq qtr qts roo rop ror ros rot rpo rpp rpr rps rpt rqs rrp rrq rrr rrs rrt rso rsp rsq rsr rss rst rto rtp rtq rtr rts rtt soo sop soq sor sos sot spo spp spq spr sps spt sqq sqr sqs sr- sro srp srq srr srs srt ss- sso ssp ssq ssr sss sst sto stp stq str sts stt to- too top toq tor tos tot tpo tpp tpq tpr tps tpt tqo tro trp trq trr trs trt tso tsp tsq tsr tss tst tto ttp ttr tts ttt