-ol fff ffl ffo ffr ffs fft flf fll flo flr fls flt fof fol foo for fos fot frf frl fro frr frs frt fsf fsl fso fsr fss fst ftf ftl fto ftr fts ftt lff lfl lfo lfr lfs lft llf lll llo llr lls llt lof lol loo lor los lot lrf lro lrr lrs lrt lsf lsl lso lsr lss lst ltf ltl lto ltr lts ltt of- off ofl ofo ofr ofs oft olf oll olo ols olt oo- oof ool ooo oor oos oot or- orf orl oro orr ors ort os- osf osl oso osr oss ost ot- otf otl oto otr ots ott rff rfl rfo rfr rfs rft rlf rll rlo rlr rls rlt rof rol roo ror ros rot rrf rrl rrr rrs rrt rsf rsl rso rsr rss rst rtf rtl rto rtr rts rtt sff sfl sfo sfr sfs sft slf sll slo slr sls slt sof sol soo sor sos sot sr- srf srl sro srr srs srt ss- ssf ssl sso ssr sss sst stf stl sto str sts stt tff tfl tfo tfr tfs tft tlf tll tlo tlr tls tlt to- tof tol too tor tos tot trf trl tro trr trs trt tsf tsl tso tsr tss tst ttf ttl tto ttr tts ttt