-er eee eer ees eex eqe eqq eqs equ ere erq err ers eru es- ese esq esr ess esu esx eu- eue eur eus eux ex- exe exr exs exu exx qee qex qqq qqu qre qrs qru qsr qu- que qur qus qux qxe re- ree req rer res reu rex rqs rrq rrr rrs rru rse rsq rsr rss rsu rsx rue rur rus ruu rux rxr rxs se- see seq ser ses seu sex sqq sqr sqs sqx sr- sre srq srr srs srx ss- sse ssq ssr sss ssu ssx sue suq sur sus suu sux sxs sxu uee uer ues ur- ure urr urs uru urx use usr uss usu usx uue uur uus uuu uxr uxu xee xeq xer xes xeu xex xrx xss xue xus xxx