-er a-a a-b a-t aaa aab aad aae aar aat aau aax ab- aba abb abd abe abr abt abu abx ad- ada adb add ade adr adt adu adx aea aeb aed aee aer aet aeu aex ar- ara arb ard are arr art aru arx at- ata atb atd ate atr att atu atx au- aua aub aud aue aur aut aux ax- axa axe axr axt axx b-u baa bab bad bae bar bat bau bax bba bbb bbd bbe bbr bbt bbu bbx bda bdb bdd bde bdr bdt bdu bdx be- bea beb bed bee ber bet beu bex bra brb brd bre brr brt bru brx bta btb btd bte btr btt btu btx bua bub bud bue bur but buu bux bxb bxd bxx daa dab dad dae dar dat dau dax dba dbb dbd dbe dbr dbt dbu dbx dda ddb ddd dde ddr ddt ddu ddx de- dea deb ded dee der det deu dex dra drb drd dre drr drt dru drx dta dtb dtd dte dtr dtt dtu dtx dua dub dud due dur dut dux dxd dxr dxt dxx eaa eab ead eae ear eat eau eax eba ebb ebd ebe ebr ebt ebu ebx ed- eda edb edd ede edr edt edu edx eea eeb eed eee eer eet eex era erb erd ere err ert eru eta etb etd ete etr ett etu etx eu- eua eub eud eue eur eut eux ex- exa exd exe exr ext exu exx ra- raa rab rad rae rar rat rau rax rba rbb rbd rbe rbr rbt rbu rbx rda rdb rdd rde rdr rdt rdu rdx re- rea reb red ree rer ret reu rex rra rrb rrd rrr rrt rru rta rtb rtd rte rtr rtt rtu rtx rua rub rud rue rur rut ruu rux rxr t-x taa tab tad tae tar tat tau tax tba tbb tbd tbe tbr tbt tbu tda tdb tdd tde tdr tdt tdu tdx te- tea teb ted tee ter tet teu tex tra trb trd tre trr trt tru trx tta ttb ttd tte ttr ttt ttu ttx tua tub tud tue tur tut tuu tux txe txt txu ua- uaa uab uad uae uar uat uau uba ubb ube ubr ubt ubu ubx uda udb udd ude udr udt udu udx uea ueb ued uee uer uet ur- ura urb urd ure urr urt uru urx uta utb utd ute utr utt utu utx uua uue uur uut uuu uxb uxr uxt uxu xaa xad xar xat xau xbe xbr xbx xda xdb xde xdr xdt xed xee xer xet xeu xex xrd xrt xrx xtr xtx xue xxx