-er b-u bbb bbc bbe bbo bbr bbt bbu bbx bcb bcc bce bco bcr bct bcu bcx be- beb bec bee beo ber bet beu bex bob boc boe boo bor bot bou box brb bre bro brr brt bru brx btb btc bte bto btr btt btu btx bub buc bue buo bur but buu bux bxb bxo bxx c-- cbb cbc cbe cbo cbr cbt cbu cbx ccb ccc cce cco ccr cct ccu ccx ce- ceb cec cee ceo cer cet ceu cex co- cob coc coe coo cor cot cou cox crb crc cre cro crr crt cru crx ctb ctc cte cto ctr ctt ctu ctx cub cuc cue cuo cur cut cuu cxc cxo cxr cxt cxx ebb ebc ebe ebo ebr ebt ebu ebx ec- ecb ecc ece eco ecr ect ecu ecx eeb eec eee eeo eer eet eex eo- eob eoc eoe eoo eor eot eou erb erc ere ero err ert eru etb etc ete eto etr ett etu etx eu- eub euc eue eur eut eux ex- exc exe exo exr ext exu exx ob- obb obc obe obo obr obt obu obx oc- ocb occ oco ocr oct ocu ocx oeb oec oee oeo oer oet oex oo- oob ooc ooo oor oot oox or- orb orc ore oro orr ort oru orx ot- otb otc ote oto otr ott otu ou- ouc oue ouo our out ox- oxb oxc oxo oxt oxx rbb rbc rbe rbo rbr rbt rbu rbx rcb rcc rce rco rcr rct rcu rcx re- reb rec ree reo rer ret reu rex rob roc roe roo ror rot rou rox rrb rrc rrr rrt rru rtb rtc rte rto rtr rtt rtu rtx rub ruc rue ruo rur rut ruu rux rxr t-x tbb tbc tbe tbo tbr tbt tbu tcb tcc tce tco tcr tct tcu tcx te- teb tec tee teo ter tet teu tex to- tob toc toe too tor tot tou tox trb trc tre tro trr trt tru trx ttb ttc tte tto ttr ttt ttu ttx tub tuc tue tuo tur tut tuu tux txe txt txu ubb ubc ube ubo ubr ubt ubu ubx ucb ucc uce uco ucr uct ucu ueb uec uee uer uet uob uoc uoe uoo uor uot uox ur- urb urc ure uro urr urt uru urx utb utc ute uto utr utt utu utx uuc uue uur uut uuu uxb uxc uxo uxr uxt uxu xbc xbe xbr xbx xcb xcr xcx xee xer xet xeu xex xoc xoo xor xot xox xrc xrt xrx xtc xtr xtx xue xxo xxx