tti ttl ttn tto ttp ttr ttt ttu tty tub tuc tui tul tun tuo tup tur tut tuu tuy tyc tyl tyn tyo typ tyr tyt ubb ubc ubi ubl ubn ubo ubp ubr ubt ubu uby ucb ucc uci ucl ucn uco ucp ucr uct ucu uib uic uii uil uin uio uip uir uit uiu ulb ulc uli ull uln ulo ulp ulr ult ulu uly un- unb unc uni unl unn uno unp unr unt unu uny uob uoc uol uon uoo uop uor uot up- upb upc upi upn upo upp upr upt upu ur- urb urc uri url urn uro urp urr urt uru ury utb utc uti utl utn uto utp utr utt utu uty uuc uun uur uut uuu uyc uyi uyo uyu ybc ybi ybl ybp ybr yby ycc yci ycl yco ycp ycu ycy yii yin yio yip yir yit ylc yli yll ylr ylt yly ynn ynp ynu yny yob yoc yoi yol yon yoo yop yor yot you yoy ypl ypo ypu yrc yrn yro yrp yrt yru ytc ytl ytn yto ytp ytr ytt ytu yui yul yun yuo yup yur yut yuu yuy yyb yyc yyt yyu yyy