ISOTRONIC

in is it no oi on or os si so ti to

cis con coo cor cos cot ins ion its nit noo nor nos not ono ons oot orc ors ort rin roc rot sic sin sir sit son sot sri tic tin tis ton too tor

cion cist coin coir coni cons coon coos coot corn cors cost cots cris crit icon inro inti into ions iris iron nisi nits noir nori onos onto oots orcs orts otic rins riot rocs root roti roto rots scot snit snot soon soot sori sorn sort stir tics tins tiro tons toon torc tori torn toro tors trio