-er a-a a-b aaa aab aad aae aak aar aav ab- aba abb abd abe abk abr abv ad- ada adb add ade adk adr adv aea aeb aed aee aek aer aev aka akb akd ake akk akr akv ar- ara arb ard are ark arr arv av- ava avb avd ave avk avr baa bab bad bae bak bar bav bba bbb bbd bbe bbk bbr bda bdb bdd bde bdk bdr bdv be- bea beb bed bee bek ber bev bka bkb bke bkk bkr bkv bra brb brd bre brk brr brv bva bvb bvd bve bvk bvr bvv daa dab dad dae dak dar dav dba dbb dbd dbe dbk dbr dbv dda ddb ddd dde ddk ddr de- dea deb ded dee dek der dev dka dkb dke dkk dkr dra drb drd dre drk drr drv dva dvb dvd dve dvk dvr eaa eab ead eae eak ear eav eba ebb ebd ebe ebk ebr ebv ed- eda edb edd ede edk edr eea eeb eed eee eek eer eev eka ekb ekd eke ekr ekv era erb erd ere erk err erv eva evb evd eve evr evv ka- kaa kab kad kae kak kar kav kba kbb kbd kbe kbk kbr kda kdb kde kdk kdr ke- kea keb ked kee kek ker kev kkb kke kkk kkr kkv kra krd krk krr krv kva kvb kvk kvr kvv ra- raa rab rad rae rak rar rav rba rbb rbd rbe rbk rbr rda rdb rdd rde rdr rdv re- rea reb red ree rek rer rev rkb rke rkk rkv rra rrb rrd rrk rrr rva rvb rvd rve rvr rvv v-a v-e vaa vab vad vae vak var vav vba vbd vbk vbr vbv vdb vdd vde vdk vdr vdv vea veb ved vee vek ver vka vkb vra vrb vrd vre vrk vrr vva vvb vvr vvv