-er -ol b-u bbb bbc bbe bbl bbo bbr bbu bbx bcb bcc bce bcl bco bcr bcu bcx be- beb bec bee bel beo ber beu bex blb blc ble bll blo blr blu blx bob boc boe bol boo bor bou box brb bre brl bro brr bru brx bub buc bue bul buo bur buu bux bxb bxl bxo bxx c-- cbb cbc cbe cbl cbo cbr cbu cbx ccb ccc cce ccl cco ccr ccu ccx ce- ceb cec cee cel ceo cer ceu cex cl- clb clc cle cll clo clr clu clx co- cob coc coe col coo cor cou cox crb crc cre crl cro crr cru crx cub cuc cue cul cuo cur cuu cxc cxl cxo cxr cxx ebb ebc ebe ebl ebo ebr ebu ebx ec- ecb ecc ece ecl eco ecr ecu ecx eeb eec eee eel eeo eer eex elb elc ele ell elo elr elu elx eo- eob eoc eoe eol eoo eor eou erb erc ere erl ero err eru eu- eub euc eue eul eur eux ex- exc exe exl exo exr exu exx lbb lbc lbe lbl lbo lbr lbu lbx lcb lcc lce lcl lco lcr lcu lcx leb lec lee lel leo ler leu lex llb llc lle lll llo llr llu lob loc loe lol loo lor lou lox lrb lrc lro lrr lru lub luc lue lul luo lur luu lux lxc lxo lxr lxx ob- obb obc obe obl obo obr obu obx oc- ocb occ ocl oco ocr ocu ocx oeb oec oee oel oeo oer oex olb olc ole oll olo olu oo- oob ooc ool ooo oor oox or- orb orc ore orl oro orr oru orx ou- ouc oue oul ouo our ox- oxb oxc oxo oxx rbb rbc rbe rbl rbo rbr rbu rbx rcb rcc rce rcl rco rcr rcu rcx re- reb rec ree rel reo rer reu rex rlc rle rll rlo rlr rlu rob roc roe rol roo ror rou rox rrb rrc rrl rrr rru rub ruc rue ruo rur ruu rux rxr ubb ubc ube ubl ubo ubr ubu ubx ucb ucc uce ucl uco ucr ucu ueb uec uee uel uer ulb ulc ule ull ulo ulr ulu uob uoc uoe uol uoo uor uox ur- urb urc ure url uro urr uru urx uuc uue uur uuu uxb uxc uxo uxr uxu xbc xbe xbl xbr xbx xcb xcl xcr xcx xee xel xer xeu xex xlb xlr xoc xoo xor xox xrc xrx xue xul xxl xxo xxx