-er a-a a-b a-c aaa aab aac aad aae aak aar aau aav ab- aba abb abc abd abe abk abr abu abv ac- aca acb acc acd ace ack acr acu acv ad- ada adb adc add ade adk adr adu adv aea aeb aec aed aee aek aer aeu aev aka akb akc akd ake akk akr aku akv ar- ara arb arc ard are ark arr aru arv au- aua aub auc aud aue auk aur auv av- ava avb avc avd ave avk avr avu b-u baa bab bac bad bae bak bar bau bav bba bbb bbc bbd bbe bbk bbr bbu bca bcb bcc bcd bce bck bcr bcu bcv bda bdb bdc bdd bde bdk bdr bdu bdv be- bea beb bec bed bee bek ber beu bev bka bkb bkc bke bkk bkr bkv bra brb brd bre brk brr bru brv bua bub buc bud bue buk bur buu bva bvb bvc bvd bve bvk bvr bvu bvv c-- caa cab cac cad cae cak car cau cav cba cbb cbc cbd cbe cbk cbr cbu cbv cca ccb ccc ccd cce cck ccr ccu ccv cda cdb cdc cdd cde cdk cdr cdu cdv ce- cea ceb cec ced cee cek cer ceu cev cka ckb ckc ckd cra crb crc crd cre crk crr cru crv cua cub cuc cud cue cuk cur cuu cuv cva cvb cvc cvd cve cvk cvr cvu cvv daa dab dac dad dae dak dar dau dav dba dbb dbc dbd dbe dbk dbr dbu dbv dca dcb dcc dcd dce dck dcr dcu dcv dda ddb ddc ddd dde ddk ddr ddu de- dea deb dec ded dee dek der deu dev dka dkb dkc dke dkk dkr dku dra drb drc drd dre drk drr dru drv dua dub duc dud due duk dur duv dva dvb dvc dvd dve dvk dvr dvu eaa eab eac ead eae eak ear eau eav eba ebb ebc ebd ebe ebk ebr ebu ebv ec- eca ecb ecc ecd ece eck ecr ecu ecv ed- eda edb edc edd ede edk edr edu eea eeb eec eed eee eek eer eev eka ekb ekc ekd eke ekr eku ekv era erb erc erd ere erk err eru erv eu- eua eub euc eud eue eur euv eva evb evc evd eve evr evv ka- kaa kab kac kad kae kak kar kau kav kba kbb kbc kbd kbe kbk kbr kbu kca kcb kcc kcd kce kck kcr kcu kda kdb kdc kde kdk kdr kdu ke- kea keb kec ked kee kek ker kev kkb kkc kke kkk kkr kku kkv kra krc krd krk krr kru krv kub kuc kud kue kuk kur kuu kva kvb kvk kvr kvv ra- raa rab rac rad rae rak rar rau rav rba rbb rbc rbd rbe rbk rbr rbu rca rcb rcc rcd rce rcr rcu rcv rda rdb rdc rdd rde rdr rdu rdv re- rea reb rec red ree rek rer reu rev rkb rkc rke rkk rku rkv rra rrb rrc rrd rrk rrr rru rua rub ruc rud rue ruk rur ruu ruv rva rvb rvc rvd rve rvr rvu rvv ua- uaa uab uac uad uae uak uar uau uav uba ubb ubc ube ubk ubr ubu ubv uca ucb ucc ucd uce uck ucr ucu ucv uda udb udc udd ude udk udr udu udv uea ueb uec ued uee uer uka ukb ukc uke ukk ukr uku ur- ura urb urc urd ure urk urr uru uua uuc uue uur uuu uva uvb uvc uve uvu uvv v-a v-e vaa vab vac vad vae vak var vau vav vba vbc vbd vbk vbr vbv vca vcc vcd vce vcr vcu vdb vdc vdd vde vdk vdr vdu vdv vea veb vec ved vee vek ver veu vka vkb vra vrb vrc vrd vre vrk vrr vru vue vuk vur vuv vva vvb vvc vvr vvv