a-a a-c a-t aaa aac aao aap aar aat ac- aca acc aco acp acr act aoa aoc aoo aop aor aot ap- apa apc apo app apr apt ar- ara arc aro arp arr art at- ata atc ato atp atr att c-- caa cac cao cap car cat cca ccc cco ccp ccr cct co- coa coc coo cop cor cot cpa cpc cpo cpp cpr cpt cra crc cro crp crr crt cta ctc cto ctp ctr ctt oaa oac oao oap oar oat oc- oca occ oco ocp ocr oct oo- ooa ooc ooo oop oor oot op- opa opc opo opp opr opt or- ora orc oro orp orr ort ot- ota otc oto otp otr ott p-p paa pac pao pap par pat pca pcc pco pcp pcr pct poa poc poo pop por pot ppa ppc ppo ppp ppr ppt pra prc pro prp prr prt pt- pta ptc pto ptp ptr ptt ra- raa rac rao rap rar rat rca rcc rco rcp rcr rct roa roc roo rop ror rot rpa rpc rpo rpp rpr rpt rra rrc rrp rrr rrt rta rtc rto rtp rtr rtt taa tac tao tap tar tat tca tcc tco tcp tcr tct to- toa toc too top tor tot tpa tpc tpo tpp tpr tpt tra trc tro trp trr trt tta ttc tto ttp ttr ttt