a-a a-b a-i a-t aaa aab aad aai aao aar aat ab- aba abb abd abi abo abr abt ad- ada adb add adi ado adr adt ai- aia aib aid aii aio air ait aoa aob aod aoi aoo aor aot ar- ara arb ard ari aro arr art at- ata atb atd ati ato atr att baa bab bad bai bao bar bat bba bbb bbd bbi bbo bbr bbt bda bdb bdd bdi bdo bdr bdt bi- bia bib bid bii bio bir bit boa bob bod boi boo bor bot bra brb brd bri bro brr brt bta btb btd bti bto btr btt daa dab dad dai dao dar dat dba dbb dbd dbi dbo dbr dbt dda ddb ddd ddi ddo ddr ddt di- dia dib did dii dio dir dit doa dob dod doi doo dor dot dra drb drd dri dro drr drt dta dtb dtd dti dto dtr dtt i-d ia- iaa iab iad iai iao iar iat iba ibb ibd ibi ibo ibr ibt ida idb idd idi ido idr idt iia iib iid iii iio iir iit io- ioa iob iod ioi ioo ior iot ir- ira irb ird iri iro irr irt ita itb itd iti ito itt o-i oaa oab oad oai oao oar oat ob- oba obb obd obi obo obr obt oda odb odd odi odo odr odt oia oib oid oii oio oir oit oo- ooa oob ood ooi ooo oor oot or- ora orb ord ori oro orr ort ot- ota otb otd oti oto otr ott ra- raa rab rad rai rao rar rat rba rbb rbd rbi rbo rbr rbt rda rdb rdd rdi rdo rdr rdt ria rib rid rii rio rir rit roa rob rod roi roo ror rot rra rrb rrd rri rrr rrt rta rtb rtd rti rto rtr rtt taa tab tad tai tao tar tat tba tbb tbd tbi tbo tbr tbt tda tdb tdd tdi tdo tdr tdt tia tib tid tii tio tir tit to- toa tob tod toi too tor tot tra trb trd tri tro trr trt tta ttb ttd tti tto ttr ttt