-er -ic a-a a-b a-c a-i aaa aab aac aae aai aak aao aar ab- aba abb abc abe abi abk abo abr ac- aca acb acc ace aci ack aco acr aea aeb aec aee aei aek aeo aer ai- aia aib aic aie aii aik aio air aka akb akc ake aki akk ako akr aoa aob aoc aoe aoi aok aoo aor ar- ara arb arc are ari ark aro arr baa bab bac bae bai bak bao bar bba bbb bbc bbe bbi bbk bbo bbr bca bcb bcc bce bci bck bco bcr be- bea beb bec bee bei bek beo ber bi- bia bib bic bie bii bik bio bir bka bkb bkc bke bkk bko bkr boa bob boc boe boi bok boo bor bra brb bre bri brk bro brr c-- caa cab cac cae cai cak cao car cba cbb cbc cbe cbi cbk cbo cbr cca ccb ccc cce cci cck cco ccr ce- cea ceb cec cee cei cek ceo cer ci- cia cib cic cie cii cik cio cir cka ckb ckc cki cko co- coa cob coc coe coi cok coo cor cra crb crc cre cri crk cro crr eaa eab eac eae eai eak eao ear eba ebb ebc ebe ebi ebk ebo ebr ec- eca ecb ecc ece eci eck eco ecr eea eeb eec eee eek eeo eer eia eib eic eie eii eik eio eir eka ekb ekc eke eki eko ekr eo- eoa eob eoc eoe eoi eok eoo eor era erb erc ere eri erk ero err ia- iaa iab iac iae iai iao iar iba ibb ibc ibe ibi ibk ibo ibr ica icb icc ice ici ick ico icr ie- iea iec iee iei iek ier iia iib iic iie iii iio iir ika ikb ikc ike iki ikk iko ikr io- ioa iob ioc ioe ioi ioo ior ir- ira irb irc ire iri irk iro irr ka- kaa kab kac kae kai kak kao kar kba kbb kbc kbe kbi kbk kbo kbr kca kcb kcc kce kci kck kcr ke- kea keb kec kee kei kek keo ker kia kib kic kie kii kik kio kir kkb kkc kke kki kkk kkr koa kob koc koe koi kok koo kor kra krc kri krk kro krr o-i oaa oab oac oae oai oak oao oar ob- oba obb obc obe obi obk obo obr oc- oca ocb occ oci ock oco ocr oea oeb oec oee oei oeo oer oia oib oic oie oii oik oio oir oka okb okc oke oki okk oko okr oo- ooa oob ooc ooi ook ooo oor or- ora orb orc ore ori ork oro orr ra- raa rab rac rae rai rak rao rar rba rbb rbc rbe rbi rbk rbo rbr rca rcb rcc rce rci rco rcr re- rea reb rec ree rei rek reo rer ria rib ric rie rii rik rio rir rkb rkc rke rkk rko roa rob roc roe roi rok roo ror rra rrb rrc rri rrk rrr