a-a a-b a-i a-t aaa aab aai aas aat aau ab- aba abb abi abs abt abu ai- aia aib aii ais ait aiu as- asa asb asi ass ast asu at- ata atb ati ats att atu au- aua aub aui aus aut b-u baa bab bai bas bat bau bba bbb bbi bbs bbt bbu bi- bia bib bii bis bit biu bsa bsb bsi bss bst bsu bta btb bti bts btt btu bua bub bui bus but buu ia- iaa iab iai ias iat iau iba ibb ibi ibs ibt ibu iia iib iii iis iit iiu is- isa isb isi iss ist isu ita itb iti its itt itu iu- iua iub iui ius iut saa sab sai sas sat sau sba sbb sbi sbs sbt sbu sia sib sii sis sit siu ss- ssa ssb ssi sss sst ssu sta stb sti sts stt stu sua sub sui sus sut suu taa tab tai tas tat tau tba tbb tbi tbs tbt tbu tia tib tii tis tit tiu tsa tsb tsi tss tst tsu tta ttb tti tts ttt ttu tua tub tui tus tut tuu ua- uaa uab uai uas uat uau uba ubb ubi ubs ubt ubu uia uib uii uis uit uiu usa usb usi uss ust usu uta utb uti uts utt utu uua uus uut uuu