-er -ic b-u bbb bbc bbd bbe bbi bbk bbr bbu bcb bcc bcd bce bci bck bcr bcu bdb bdc bdd bde bdi bdk bdr bdu be- beb bec bed bee bei bek ber beu bi- bib bic bid bie bii bik bir biu bkb bkc bke bkk bkr brb brd bre bri brk brr bru bub buc bud bue bui buk bur buu c-- cbb cbc cbd cbe cbi cbk cbr cbu ccb ccc ccd cce cci cck ccr ccu cdb cdc cdd cde cdi cdk cdr cdu ce- ceb cec ced cee cei cek cer ceu ci- cib cic cid cie cii cik cir ciu ckb ckc ckd cki crb crc crd cre cri crk crr cru cub cuc cud cue cui cuk cur cuu dbb dbc dbd dbe dbi dbk dbr dbu dcb dcc dcd dce dci dck dcr dcu ddb ddc ddd dde ddi ddk ddr ddu de- deb dec ded dee dei dek der deu di- dib dic did die dii dik dir diu dkb dkc dke dki dkk dkr dku drb drc drd dre dri drk drr dru dub duc dud due dui duk dur ebb ebc ebd ebe ebi ebk ebr ebu ec- ecb ecc ecd ece eci eck ecr ecu ed- edb edc edd ede edi edk edr edu eeb eec eed eee eek eer eib eic eid eie eii eik eir eiu ekb ekc ekd eke eki ekr eku erb erc erd ere eri erk err eru eu- eub euc eud eue eui eur i-d ibb ibc ibd ibe ibi ibk ibr ibu icb icc icd ice ici ick icr icu idb idc idd ide idi idk idr idu ie- iec ied iee iei iek ier iib iic iid iie iii iir iiu ikb ikc ike iki ikk ikr iku ir- irb irc ird ire iri irk irr iru iu- iub iuc iud iue iui iur kbb kbc kbd kbe kbi kbk kbr kbu kcb kcc kcd kce kci kck kcr kcu kdb kdc kde kdk kdr kdu ke- keb kec ked kee kei kek ker kib kic kid kie kii kik kir kiu kkb kkc kke kki kkk kkr kku krc krd kri krk krr kru kub kuc kud kue kui kuk kur kuu rbb rbc rbd rbe rbi rbk rbr rbu rcb rcc rcd rce rci rcr rcu rdb rdc rdd rde rdi rdr rdu re- reb rec red ree rei rek rer reu rib ric rid rie rii rik rir rkb rkc rke rkk rku rrb rrc rrd rri rrk rrr rru rub ruc rud rue rui ruk rur ruu ubb ubc ube ubi ubk ubr ubu ucb ucc ucd uce uci uck ucr ucu udb udc udd ude udi udk udr udu ueb uec ued uee uei uer uib uic uid uie uii uir uiu ukb ukc uke uki ukk ukr uku ur- urb urc urd ure uri urk urr uru uuc uue uur uuu