ffff ffrr ffss fftf fnrs fofo fono fons font foof foon foos foot for- forn foro forr fors fort foso foss fost foto fots fott frns fron fros frot frso frst fsfo fssf ftos ftrs ftsr nfff nfon nfrs nfsr nfto nnnn nnos nnot nnss nntn non- nonn nono nons nont noo- noon nooo noor noos noot nor- norf norn noro norr nors nort nos- noss nost not- noto nots nott nron nrts nsfs nsnr nsof nsos nssf nsso nssr nsss nsts ntfs ntof ntsf ntss ntto nttr off- offo offr offs ofno ofor ofst onno onon onor onos onso onst ont- onto ooff oofs oons oont oooo ooos oort oost oots orff orfs orno orns oro- orof oron oror oros orot orro orrs orso orto orts osno osnr osoo osor osos osro osso ostr osts oto- otof oton otoo otor otos otro otrs otso otto otts rnnt rnot roff rofo rono rons ront roof roon roor roos root roro rort roso ross rost rotn roto rotr rots rott rrrr rsnn rsno rsnr rsos rsts rtns rtss rtts s-os sfnt sfor sfos sfro sfss sfts snns snoo snor snos snot snrs sntr sofo soft son- sono sons sont soof soon soor soos soot sorn soro sorr sors sort soso soss sost sotn soto sots srnn srno sros srtr ssns ssot ssrs sssf ssss ssts stfn stnn stnr stns stof ston stoo stor stos stot strn stro strs stsf stss sttr tfot tfrs tfss tnts toff tofo toft tonn tono tons toof toon toor toos toot torf torn toro torr tors tort toso toss tost toto totr tots tott trfr trno tron troo tros trot trst trtr tsos tssf tssr tsst tsts ttff ttfn tton ttss tttt