-er a-a a-b aaa aab aad aae aar aau aav ab- aba abb abd abe abr abu abv ad- ada adb add ade adr adu adv aea aeb aed aee aer aeu aev ar- ara arb ard are arr aru arv au- aua aub aud aue aur auv av- ava avb avd ave avr avu b-u baa bab bad bae bar bau bav bba bbb bbd bbe bbr bbu bda bdb bdd bde bdr bdu bdv be- bea beb bed bee ber beu bev bra brb brd bre brr bru brv bua bub bud bue bur buu bva bvb bvd bve bvr bvu bvv daa dab dad dae dar dau dav dba dbb dbd dbe dbr dbu dbv dda ddb ddd dde ddr ddu de- dea deb ded dee der deu dev dra drb drd dre drr dru drv dua dub dud due dur duv dva dvb dvd dve dvr dvu eaa eab ead eae ear eau eav eba ebb ebd ebe ebr ebu ebv ed- eda edb edd ede edr edu eea eeb eed eee eer eev era erb erd ere err eru erv eu- eua eub eud eue eur euv eva evb evd eve evr evv ra- raa rab rad rae rar rau rav rba rbb rbd rbe rbr rbu rda rdb rdd rde rdr rdu rdv re- rea reb red ree rer reu rev rra rrb rrd rrr rru rua rub rud rue rur ruu ruv rva rvb rvd rve rvr rvu rvv ua- uaa uab uad uae uar uau uav uba ubb ube ubr ubu ubv uda udb udd ude udr udu udv uea ueb ued uee uer ur- ura urb urd ure urr uru uua uue uur uuu uva uvb uve uvu uvv v-a v-e vaa vab vad vae var vau vav vba vbd vbr vbv vdb vdd vde vdr vdu vdv vea veb ved vee ver veu vra vrb vrd vre vrr vru vue vur vuv vva vvb vvr vvv