a-a a-b a-i a-t aaa aab aad aai aar aat ab- aba abb abd abi abr abt ad- ada adb add adi adr adt ai- aia aib aid aii air ait ar- ara arb ard ari arr art at- ata atb atd ati atr att baa bab bad bai bar bat bba bbb bbd bbi bbr bbt bda bdb bdd bdi bdr bdt bi- bia bib bid bii bir bit bra brb brd bri brr brt bta btb btd bti btr btt daa dab dad dai dar dat dba dbb dbd dbi dbr dbt dda ddb ddd ddi ddr ddt di- dia dib did dii dir dit dra drb drd dri drr drt dta dtb dtd dti dtr dtt i-d ia- iaa iab iad iai iar iat iba ibb ibd ibi ibr ibt ida idb idd idi idr idt iia iib iid iii iir iit ir- ira irb ird iri irr irt ita itb itd iti itt ra- raa rab rad rai rar rat rba rbb rbd rbi rbr rbt rda rdb rdd rdi rdr rdt ria rib rid rii rir rit rra rrb rrd rri rrr rrt rta rtb rtd rti rtr rtt taa tab tad tai tar tat tba tbb tbd tbi tbr tbt tda tdb tdd tdi tdr tdt tia tib tid tii tir tit tra trb trd tri trr trt tta ttb ttd tti ttr ttt