fff ffi ffo ffs fft ffy fif fii fis fit fof foi foo fos fot foy fsf fsi fso fss fst ftf fti fto fts ftt fty fy- fyi fyo i-f iff ifi ifo ifs ift ify iif iii iio iis iit io- iof ioi ioo ios iot is- isf isi iso iss ist isy itf iti ito its itt ity iyo iys iyt iyy o-i of- off ofi ofo ofs oft oif oii oio ois oit oo- oof ooi ooo oos oot os- osf osi oso oss ost ot- otf oti oto ots ott oyi oyo oys sff sfi sfo sfs sft sif sii sio sis sit sof soi soo sos sot soy ss- ssf ssi sso sss sst stf sti sto sts stt sty sy- syi sys syt tff tfi tfo tfs tft tif tii tio tis tit tiy to- tof toi too tos tot toy tsf tsi tso tss tst tsy ttf tti tto tts ttt tty tyf tyo tys tyt yff yfs yft yif yii yio yis yit yof yoi yoo yos yot yoy ysi yso yss yst ysy ytf yto yts ytt yyf yys yyt yyy