nipo[5], pion[5], inro[4], iron[4], nori[4], orni[4], roni[4],
nip[4], pin[4], pni[4], poi[4], por[4], pro[4], rop[4], ino[3], oni[3], inr[3], roi[3], nor[3],
pi[3], op[3], po[3], in[2], ni[2], no[2], on[2], or[2], ro[2],
