a-a a-b a-t aaa aab aad aaf aao aar aat aau ab- aba abb abd abf abo abr abt abu ad- ada adb add adf ado adr adt adu af- afa afb afd aff afo afr aft afu aoa aob aod aof aoo aor aot aou ar- ara arb ard arf aro arr art aru at- ata atb atd atf ato atr att atu au- aua aub aud auf auo aur aut b-u baa bab bad baf bao bar bat bau bba bbb bbd bbf bbo bbr bbt bbu bda bdb bdd bdf bdo bdr bdt bdu bfa bfb bfd bff bfo bfr bft bfu boa bob bod bof boo bor bot bou bra brb brd brf bro brr brt bru bta btb btd btf bto btr btt btu bua bub bud buf buo bur but buu daa dab dad daf dao dar dat dau dba dbb dbd dbf dbo dbr dbt dbu dda ddb ddd ddf ddo ddr ddt ddu dfa dfb dfd dff dfo dfr dft dfu doa dob dod dof doo dor dot dou dra drb drd dro drr drt dru dta dtb dtd dtf dto dtr dtt dtu dua dub dud duf duo dur dut faa fab fad faf fao far fat fau fba fbb fbd fbf fbo fbr fbt fbu fda fdb fdd fdf fdo fdr fdt fdu ffa ffd fff ffo ffr fft ffu foa fob fof foo for fot fou fra frb frd frf fro frr frt fru fta ftb ftd ftf fto ftr ftt ftu fua fub fud fuf fuo fur fut fuu oaa oab oad oaf oao oar oat oau ob- oba obb obd obf obo obr obt obu oda odb odd odf odo odr odt odu of- ofa ofb ofd off ofo ofr oft ofu oo- ooa oob ood oof ooo oor oot or- ora orb ord orf oro orr ort oru ot- ota otb otd otf oto otr ott otu ou- oua oud ouf ouo our out ra- raa rab rad raf rao rar rat rau rba rbb rbd rbf rbo rbr rbt rbu rda rdb rdd rdf rdo rdr rdt rdu rfa rfb rfd rff rfo rfr rft rfu roa rob rod rof roo ror rot rou rra rrb rrd rrf rrr rrt rru rta rtb rtd rtf rto rtr rtt rtu rua rub rud ruf ruo rur rut ruu taa tab tad taf tao tar tat tau tba tbb tbd tbf tbo tbr tbt tbu tda tdb tdd tdf tdo tdr tdt tdu tfa tfb tfd tff tfo tfr tft tfu to- toa tob tod tof too tor tot tou tra trb trd trf tro trr trt tru tta ttb ttd ttf tto ttr ttt ttu tua tub tud tuf tuo tur tut tuu ua- uaa uab uad uaf uao uar uat uau uba ubb ubf ubo ubr ubt ubu uda udb udd udf udo udr udt udu ufa ufd uff ufo ufr uft ufu uoa uob uod uoo uor uot ur- ura urb urd urf uro urr urt uru uta utb utd utf uto utr utt utu uua uur uut uuu