fff ffi ffo ffr ffs ffy fif fii fir fis fof foi foo for fos foy frf fri fro frr frs fry fsf fsi fso fsr fss fy- fyi fyo i-f iff ifi ifo ifr ifs ify iif iii iio iir iis io- iof ioi ioo ior ios ir- irf iri iro irr irs iry is- isf isi iso isr iss isy iyo iyr iys iyy o-i of- off ofi ofo ofr ofs oif oii oio oir ois oo- oof ooi ooo oor oos or- orf ori oro orr ors ory os- osf osi oso osr oss oyi oyo oys rff rfi rfo rfr rfs rif rii rio rir ris riy rof roi roo ror ros roy rrf rri rrr rrs rsf rsi rso rsr rss ry- ryf ryo ryr rys ryy sff sfi sfo sfr sfs sif sii sio sir sis sof soi soo sor sos soy sr- srf sri sro srr srs sry ss- ssf ssi sso ssr sss sy- syi syr sys yff yfr yfs yif yii yio yir yis yof yoi yoo yor yos yoy yrf yro yrs ysi yso ysr yss ysy yyf yys yyy