fff ffi ffk ffl ffs fif fii fik fil fis fkf fki fkk fkl flf fli fll fls fsf fsi fsk fsl fss i-f iff ifi ifl ifs iif iii iil iis ikf iki ikk ikl iks il- ilf ili ilk ill ils is- isf isi isk isl iss kff kfi kfs kif kii kik kil kis kki kkk kkl kks kl- klf kli kls ksf ksi ksk ksl kss lff lfi lfk lfl lfs lif lii lik lil lis lkl lks llf lli llk lll lls lsf lsi lsk lsl lss sff sfi sfk sfl sfs sif sii sik sil sis sk- skf ski skk skl sks slf sli slk sll sls ss- ssf ssi ssk ssl sss