a-a a-b a-t aaa aab aad aas aat aau aay ab- aba abb abd abs abt abu aby ad- ada adb add ads adt adu ady as- asa asb asd ass ast asu asy at- ata atb atd ats att atu au- aua aub aud aus aut ay- aya ayd ays ayt ayu b-u baa bab bad bas bat bau bay bba bbb bbd bbs bbt bbu bby bda bdb bdd bds bdt bdu bdy bsa bsb bsd bss bst bsu bsy bta btb btd bts btt btu bty bua bub bud bus but buu buy by- bya byd bys byt byu daa dab dad das dat dau day dba dbb dbd dbs dbt dbu dby dda ddb ddd dds ddt ddu ddy dsa dsb dsd dss dst dsu dsy dta dtb dtd dts dtt dtu dty dua dub dud dus dut duy dy- dya dyb dyd dys dyu dyy saa sab sad sas sat sau say sba sbb sbd sbs sbt sbu sby sda sdb sdd sds sdt sdu sdy ss- ssa ssb ssd sss sst ssu sta stb std sts stt stu sty sua sub sud sus sut suu suy sy- sya syb syd sys syt syu taa tab tad tas tat tau tay tba tbb tbd tbs tbt tbu tda tdb tdd tds tdt tdu tdy tsa tsb tsd tss tst tsu tsy tta ttb ttd tts ttt ttu tty tua tub tud tus tut tuu tuy tya tyd tys tyt ua- uaa uab uad uas uat uau uay uba ubb ubs ubt ubu uby uda udb udd uds udt udu usa usb usd uss ust usu uta utb utd uts utt utu uty uua uus uut uuu uys uyu yaa yab yad yas yat yau yay ybs yby yda yds ydt ydy ysa ysb yss yst ysu ysy yta ytd yts ytt ytu yua yud yus yut yuu yuy yyb yys yyt yyu yyy