-er -ic bbb bbc bbe bbi bbk bbo bbr bbx bcb bcc bce bci bck bco bcr bcx be- beb bec bee bei bek beo ber bex bi- bib bic bie bii bik bio bir bix bkb bkc bke bkk bko bkr bkx bob boc boe boi bok boo bor box brb bre bri brk bro brr brx bxb bxi bxo bxx c-- cbb cbc cbe cbi cbk cbo cbr cbx ccb ccc cce cci cck cco ccr ccx ce- ceb cec cee cei cek ceo cer cex ci- cib cic cie cii cik cio cir cix ckb ckc cki cko ckx co- cob coc coe coi cok coo cor cox crb crc cre cri crk cro crr crx cxc cxi cxk cxo cxr cxx ebb ebc ebe ebi ebk ebo ebr ebx ec- ecb ecc ece eci eck eco ecr ecx eeb eec eee eek eeo eer eex eib eic eie eii eik eio eir eix ekb ekc eke eki eko ekr eo- eob eoc eoe eoi eok eoo eor erb erc ere eri erk ero err ex- exc exe exi exo exr exx ibb ibc ibe ibi ibk ibo ibr ibx icb icc ice ici ick ico icr ie- iec iee iei iek ier iex iib iic iie iii iio iir iix ikb ikc ike iki ikk iko ikr ikx io- iob ioc ioe ioi ioo ior ir- irb irc ire iri irk iro irr irx ixc ixe ixi kbb kbc kbe kbi kbk kbo kbr kbx kcb kcc kce kci kck kcr kcx ke- keb kec kee kei kek keo ker kex kib kic kie kii kik kio kir kix kkb kkc kke kki kkk kkr kob koc koe koi kok koo kor krc kri krk kro krr kxo o-i ob- obb obc obe obi obk obo obr obx oc- ocb occ oci ock oco ocr ocx oeb oec oee oei oeo oer oex oib oic oie oii oik oio oir okb okc oke oki okk oko okr oo- oob ooc ooi ook ooo oor oox or- orb orc ore ori ork oro orr orx ox- oxb oxc oxi oxo oxx rbb rbc rbe rbi rbk rbo rbr rbx rcb rcc rce rci rco rcr rcx re- reb rec ree rei rek reo rer rex rib ric rie rii rik rio rir rix rkb rkc rke rkk rko rob roc roe roi rok roo ror rox rrb rrc rri rrk rrr rxr xbc xbe xbr xbx xcb xci xcr xcx xee xer xex xic xie xii xio xix xkb xke xoc xoi xok xoo xor xox xrc xrx xxi xxo xxx