rillt[7], still[7], stils[6], risst[5],
tics[7], rill[6], till[6], list[5], stil[5], riss[4], sirs[4], rist[4], isst[4],
cis[6], sic[6], tic[6], sir[3], iss[3], ist[3],
si[2], ti[2], st[2],