fff ffi ffn ffo ffr ffs fft ffx fif fii fin fir fis fit fix fnf fni fnn fnr fns fnt fnx fof foi fon foo for fos fot fox frf fri frn fro frr frs frt fsf fsi fsn fso fsr fss fst fsx ftf fti ftn fto ftr fts ftt ftx fxi fxr fxs fxt fxx i-f iff ifi ifn ifo ifr ifs ift ifx iif iii iin iio iir iis iit iix in- inf ini inn ino inr ins int inx io- iof ioi ion ioo ior ios iot ir- irf iri irn iro irr irs irt irx is- isf isi isn iso isr iss ist itf iti itn ito its itt itx ixi ixn n-i nff nfi nfn nfo nfr nfs nft nif nii nin nio nir nis nit nix nnf nni nnn nno nns nnt no- nof noi non noo nor nos not nox nrf nri nrn nro nrr nrs nrt nrx nsf nsi nsn nso nsr nss nst nsx ntf nti ntn nto ntr nts ntt ntx nxt o-i of- off ofi ofn ofo ofr ofs oft ofx oif oii oin oio oir ois oit on- onf oni onn ono onr ons ont onx oo- oof ooi oon ooo oor oos oot oox or- orf ori orn oro orr ors ort orx os- osf osi osn oso osr oss ost osx ot- otf oti otn oto otr ots ott ox- oxf oxi oxn oxo oxt oxx rff rfi rfn rfo rfr rfs rft rif rii rin rio rir ris rit rix rni rnn rno rnr rns rnt rof roi ron roo ror ros rot rox rrf rri rrn rrr rrs rrt rsf rsi rsn rso rsr rss rst rsx rtf rti rtn rto rtr rts rtt rtx rxr rxs sff sfi sfn sfo sfr sfs sft sfx sif sii sin sio sir sis sit six snf sni snn sno snr sns snt sof soi son soo sor sos sot sox sr- srf sri srn sro srr srs srt srx ss- ssf ssi ssn sso ssr sss sst ssx stf sti stn sto str sts stt stx sxi sxn sxs sxt t-x tff tfi tfn tfo tfr tfs tft tfx tif tii tin tio tir tis tit tix tnf tni tnn tno tnr tns tnt tnx to- tof toi ton too tor tos tot tox trf tri trn tro trr trs trt trx tsf tsi tsn tso tsr tss tst tsx ttf tti ttn tto ttr tts ttt ttx txf txi txn txs txt xfn xfs xft xfx xii xin xio xis xit xix xno xns xof xoi xon xoo xor xos xot xox xrf xrt xrx xsi xss xst xtf xti xtr xts xtx xxi xxo xxx