fff ffi ffk ffn ffs fif fii fik fin fis fkf fki fkk fnf fni fnk fnn fns fsf fsi fsk fsn fss i-f iff ifi ifn ifs iif iii iin iis ikf iki ikk iks in- inf ini ink inn ins is- isf isi isk isn iss kff kfi kfs kif kii kik kin kis kki kkk kkn kks kn- knf kni knk knn ksf ksi ksk ksn kss n-i nff nfi nfk nfn nfs nif nii nik nin nis nkf nki nkk nkn nks nnf nni nnk nnn nns nsf nsi nsk nsn nss sff sfi sfk sfn sfs sif sii sik sin sis sk- skf ski skk sks snf sni snk snn sns ss- ssf ssi ssk ssn sss