fff ffo ffr ffs ffw fof foo for fos fow frf fro frr frs frw fsf fso fsr fss fsw fwf fwo fws of- off ofo ofr ofs ofw oo- oof ooo oor oos oow or- orf oro orr ors os- osf oso osr oss osw owf owo ows oww rff rfo rfr rfs rfw rof roo ror ros row rrf rrr rrs rsf rso rsr rss rsw rwf rwr rws sff sfo sfr sfs sfw sof soo sor sos sow sr- srf sro srr srs srw ss- ssf sso ssr sss ssw swf swo swr sws wff wfo wfr wfs wfw wof woo wor wos wow wr- wrf wro wrr wrs wrw wsf wso wsr wss wsw wwf wwo www