fff ffg ffi ffo ffs fgf fgg fgi fgs fif fig fii fis fof fog foi foo fos fsf fsg fsi fso fss gff gfi gfo gfs ggg ggi ggo ggs gif gig gii gio gis gof gog goi goo gos gsf gsg gsi gso gss i-f iff ifg ifi ifo ifs igf igg igi igo igs iif iii iio iis io- iof iog ioi ioo ios is- isf isg isi iso iss o-i of- off ofg ofi ofo ofs ogf ogg ogi ogo ogs oif oii oio ois oo- oof oog ooi ooo oos os- osf osg osi oso oss sff sfg sfi sfo sfs sgf sgg sgi sgo sgs sif sig sii sio sis sof sog soi soo sos ss- ssf ssg ssi sso sss