-er -ic a-a a-b a-c a-i aaa aab aac aae aag aai aak aar ab- aba abb abc abe abg abi abk abr ac- aca acb acc ace acg aci ack acr aea aeb aec aee aeg aei aek aer ag- aga agb agc age agg agi agk agr ai- aia aib aic aie aig aii aik air aka akb akc ake akg aki akk akr ar- ara arb arc are arg ari ark arr baa bab bac bae bag bai bak bar bba bbb bbc bbe bbg bbi bbk bbr bca bcb bcc bce bcg bci bck bcr be- bea beb bec bee beg bei bek ber bga bgb bgc bge bgg bgi bgk bgr bi- bia bib bic bie big bii bik bir bka bkb bkc bke bkg bkk bkr bra brb bre brg bri brk brr c-- caa cab cac cae cag cai cak car cba cbb cbc cbe cbg cbi cbk cbr cca ccb ccc cce ccg cci cck ccr ce- cea ceb cec cee ceg cei cek cer cga cgb cgc cge cgg cgi cgr ci- cia cib cic cie cig cii cik cir cka ckb ckc cki cra crb crc cre crg cri crk crr eaa eab eac eae eag eai eak ear eba ebb ebc ebe ebg ebi ebk ebr ec- eca ecb ecc ece ecg eci eck ecr eea eeb eec eee eeg eek eer ega egb egc ege egg egi egr eia eib eic eie eig eii eik eir eka ekb ekc eke ekg eki ekr era erb erc ere erg eri erk err gaa gab gac gae gag gai gak gar gba gbc gbe gbg gbi gbk gbr gca gcb gcc gce gcg gci gck gcr ge- gea geb gec gee geg gei gek ger gga ggb ggc ggg ggi ggr gia gib gic gie gig gii gik gir gka gkb gra grb grc gre grg gri grk grr ia- iaa iab iac iae iag iai iar iba ibb ibc ibe ibg ibi ibk ibr ica icb icc ice icg ici ick icr ie- iea iec iee ieg iei iek ier iga igb igc ige igg igi igk igr iia iib iic iie iii iir ika ikb ikc ike iki ikk ikr ir- ira irb irc ire irg iri irk irr ka- kaa kab kac kae kag kai kak kar kba kbb kbc kbe kbi kbk kbr kca kcb kcc kce kcg kci kck kcr ke- kea keb kec kee keg kei kek ker kga kgb kgc kgi kia kib kic kie kig kii kik kir kkb kkc kke kki kkk kkr kra krc krg kri krk krr ra- raa rab rac rae rag rai rak rar rba rbb rbc rbe rbg rbi rbk rbr rca rcb rcc rce rcg rci rcr re- rea reb rec ree reg rei rek rer rga rgb rgc rge rgg rgi rgk rgr ria rib ric rie rig rii rik rir rkb rkc rke rkg rkk rra rrb rrc rrg rri rrk rrr