aaaa aaab aaas aaav aaba aabb aabt aasa aass aast aata aatt aava abaa abab abas abat abb- abba abbb abbs abbt abs- absa abss abta abts abva asaa asab asas asat asba assa asss asst asta astb asts astv asva asvs at-t ataa atab atas atat atbs atsb atst atta atts atvs avab avas avat avst avva baaa baas baat baba babb babs basa bass bast bata bats batt bava bbas bbbb bbbs bsaa bsas bsat bsts bstv btaa btss bttb s-vt saab saas saat saba sabb sabs sasa sass sast sata satb sats satt sava savs sbaa sbas sbbs sbsa sbst ssaa ssab ssas ssat sssa sssb ssss ssta sstb ssts st-v stab stas stat stbs stss stvs taa- taas taat taba tabb tabs tasa tasb tass tast tata tatb tats tatt tatv tava tavs tbas tbbs tbst tbta tsaa tsat tsav tssa tsst tsts ttab ttbb ttss tttt tvbs tvsa tvss tvtv vaas vaat vabs vas- vasa vass vast vata vats vatt vava vavs vsta vvsb vvvv