-er a-a a-b a-i aaa aab aad aae aai aar aau aax ab- aba abb abd abe abi abr abu abx ad- ada adb add ade adi adr adu adx aea aeb aed aee aei aer aeu aex ai- aia aib aid aie aii air aiu aix ar- ara arb ard are ari arr aru arx au- aua aub aud aue aui aur aux ax- axa axe axi axr axx b-u baa bab bad bae bai bar bau bax bba bbb bbd bbe bbi bbr bbu bbx bda bdb bdd bde bdi bdr bdu bdx be- bea beb bed bee bei ber beu bex bi- bia bib bid bie bii bir biu bix bra brb brd bre bri brr bru brx bua bub bud bue bui bur buu bux bxb bxd bxi bxx daa dab dad dae dai dar dau dax dba dbb dbd dbe dbi dbr dbu dbx dda ddb ddd dde ddi ddr ddu ddx de- dea deb ded dee dei der deu dex di- dia dib did die dii dir diu dix dra drb drd dre dri drr dru drx dua dub dud due dui dur dux dxd dxi dxr dxx eaa eab ead eae eai ear eau eax eba ebb ebd ebe ebi ebr ebu ebx ed- eda edb edd ede edi edr edu edx eea eeb eed eee eer eex eia eib eid eie eii eir eiu eix era erb erd ere eri err eru eu- eua eub eud eue eui eur eux ex- exa exd exe exi exr exu exx i-d ia- iaa iab iad iae iai iar iau iba ibb ibd ibe ibi ibr ibu ibx ida idb idd ide idi idr idu idx ie- iea ied iee iei ier iex iia iib iid iie iii iir iiu iix ir- ira irb ird ire iri irr iru irx iu- iua iub iud iue iui iur ixe ixi ra- raa rab rad rae rai rar rau rax rba rbb rbd rbe rbi rbr rbu rbx rda rdb rdd rde rdi rdr rdu rdx re- rea reb red ree rei rer reu rex ria rib rid rie rii rir rix rra rrb rrd rri rrr rru rua rub rud rue rui rur ruu rux rxr ua- uaa uab uad uae uai uar uau uba ubb ube ubi ubr ubu ubx uda udb udd ude udi udr udu udx uea ueb ued uee uei uer uia uib uid uie uii uir uiu ur- ura urb urd ure uri urr uru urx uua uue uur uuu uxb uxr uxu xaa xad xar xau xbe xbr xbx xda xdb xde xdi xdr xed xee xer xeu xex xia xie xii xiu xix xrd xrx xue xui xxi xxx