-er a-a a-b a-t aaa aab aae aao aar aat aau aax ab- aba abb abe abo abr abt abu abx aea aeb aee aeo aer aet aeu aex aoa aob aoe aoo aor aot aou aox ar- ara arb are aro arr art aru arx at- ata atb ate ato atr att atu atx au- aua aub aue auo aur aut aux ax- axa axe axo axr axt axx b-u baa bab bae bao bar bat bau bax bba bbb bbe bbo bbr bbt bbu bbx be- bea beb bee beo ber bet beu bex boa bob boe boo bor bot bou box bra brb bre bro brr brt bru brx bta btb bte bto btr btt btu btx bua bub bue buo bur but buu bux bxb bxo bxx eaa eab eae eao ear eat eau eax eba ebb ebe ebo ebr ebt ebu ebx eea eeb eee eeo eer eet eex eo- eoa eob eoe eoo eor eot eou era erb ere ero err ert eru eta etb ete eto etr ett etu etx eu- eua eub eue eur eut eux ex- exa exe exo exr ext exu exx oaa oab oae oao oar oat oau oax ob- oba obb obe obo obr obt obu obx oea oeb oee oeo oer oet oex oo- ooa oob ooo oor oot oox or- ora orb ore oro orr ort oru orx ot- ota otb ote oto otr ott otu ou- oua oue ouo our out ox- oxa oxb oxo oxt oxx ra- raa rab rae rao rar rat rau rax rba rbb rbe rbo rbr rbt rbu rbx re- rea reb ree reo rer ret reu rex roa rob roe roo ror rot rou rox rra rrb rrr rrt rru rta rtb rte rto rtr rtt rtu rtx rua rub rue ruo rur rut ruu rux rxr t-x taa tab tae tao tar tat tau tax tba tbb tbe tbo tbr tbt tbu te- tea teb tee teo ter tet teu tex to- toa tob toe too tor tot tou tox tra trb tre tro trr trt tru trx tta ttb tte tto ttr ttt ttu ttx tua tub tue tuo tur tut tuu tux txe txt txu ua- uaa uab uae uao uar uat uau uba ubb ube ubo ubr ubt ubu ubx uea ueb uee uer uet uoa uob uoe uoo uor uot uox ur- ura urb ure uro urr urt uru urx uta utb ute uto utr utt utu utx uua uue uur uut uuu uxb uxo uxr uxt uxu xaa xar xat xau xbe xbr xbx xee xer xet xeu xex xoa xoo xor xot xox xrt xrx xtr xtx xue xxo xxx