fff ffi ffk ffm ffo ffs fif fii fik fim fis fkf fki fkk fkm fmf fmi fmm fmo fms fof foi fok fom foo fos fsf fsi fsk fsm fso fss i-f iff ifi ifm ifo ifs iif iii iim iio iis ikf iki ikk iko iks im- imf imi imm imo ims io- iof ioi iom ioo ios is- isf isi isk ism iso iss kff kfi kfm kfo kfs kif kii kik kim kio kis kki kkk kkm kks kmf kmi kmk kmm kmo kms kof koi kok kom koo kos ksf ksi ksk ksm kso kss m-f m-o mff mfi mfm mfo mfs mi- mif mii mik mim mio mis mkk mkm mko mks mmf mmi mmk mmm mmo mms mof moi mok mom moo mos msf msi msk msm mso mss o-i of- off ofi ofm ofo ofs oif oii oik oim oio ois oki okk oko oks om- omf omi omm omo oms oo- oof ooi ook oom ooo oos os- osf osi osk osm oso oss sff sfi sfk sfm sfo sfs sif sii sik sim sio sis sk- skf ski skk skm sko sks smf smi smk smm smo sms sof soi sok som soo sos ss- ssf ssi ssk ssm sso sss