fff ffi ffn ffr ffs fif fii fin fir fis fnf fni fnn fnr fns frf fri frn frr frs fsf fsi fsn fsr fss i-f iff ifi ifn ifr ifs iif iii iin iir iis in- inf ini inn inr ins ir- irf iri irn irr irs is- isf isi isn isr iss n-i nff nfi nfn nfr nfs nif nii nin nir nis nnf nni nnn nns nrf nri nrn nrr nrs nsf nsi nsn nsr nss rff rfi rfn rfr rfs rif rii rin rir ris rni rnn rnr rns rrf rri rrn rrr rrs rsf rsi rsn rsr rss sff sfi sfn sfr sfs sif sii sin sir sis snf sni snn snr sns sr- srf sri srn srr srs ss- ssf ssi ssn ssr sss