-er -ic bbb bbc bbe bbi bbk bbo bbr bcb bcc bce bci bck bco bcr bcv be- beb bec bee bei bek beo ber bev bi- bib bic bie bii bik bio bir biv bkb bkc bke bkk bko bkr bkv bob boc boe boi bok boo bor bov brb bre bri brk bro brr brv bvb bvc bve bvi bvk bvo bvr bvv c-- cbb cbc cbe cbi cbk cbo cbr cbv ccb ccc cce cci cck cco ccr ccv ce- ceb cec cee cei cek ceo cer cev ci- cib cic cie cii cik cio cir civ ckb ckc cki cko co- cob coc coe coi cok coo cor cov crb crc cre cri crk cro crr crv cvb cvc cve cvi cvk cvo cvr cvv ebb ebc ebe ebi ebk ebo ebr ebv ec- ecb ecc ece eci eck eco ecr ecv eeb eec eee eek eeo eer eev eib eic eie eii eik eio eir eiv ekb ekc eke eki eko ekr ekv eo- eob eoc eoe eoi eok eoo eor erb erc ere eri erk ero err erv evb evc eve evi evo evr evv i-v ibb ibc ibe ibi ibk ibo ibr ibv icb icc ice ici ick ico icr icv ie- iec iee iei iek ier iev iib iic iie iii iio iir ikb ikc ike iki ikk iko ikr ikv io- iob ioc ioe ioi ioo ior iov ir- irb irc ire iri irk iro irr irv ivb ivc ive ivi ivo ivr ivv kbb kbc kbe kbi kbk kbo kbr kcb kcc kce kci kck kcr ke- keb kec kee kei kek keo ker kev kib kic kie kii kik kio kir kiv kkb kkc kke kki kkk kkr kkv kob koc koe koi kok koo kor krc kri krk kro krr krv kvb kvi kvk kvo kvr kvv o-i ob- obb obc obe obi obk obo obr obv oc- ocb occ oci ock oco ocr ocv oeb oec oee oei oeo oer oib oic oie oii oik oio oir oiv okb okc oke oki okk oko okr oo- oob ooc ooi ook ooo oor oov or- orb orc ore ori ork oro orr orv ov- ovb ovc ove ovi ovo ovv rbb rbc rbe rbi rbk rbo rbr rcb rcc rce rci rco rcr rcv re- reb rec ree rei rek reo rer rev rib ric rie rii rik rio rir riv rkb rkc rke rkk rko rkv rob roc roe roi rok roo ror rov rrb rrc rri rrk rrr rvb rvc rve rvi rvo rvr rvv v-e vbc vbi vbk vbo vbr vbv vcc vce vci vco vcr veb vec vee vei vek veo ver vi- vib vic vie vii vik vio vir viv vkb vob voc voe voi vok voo vor vov vrb vrc vre vri vrk vrr vvb vvc vvi vvo vvr vvv