-er -ic a-a a-b a-c a-i aaa aab aac aae aag aai aar aas ab- aba abb abc abe abg abi abr abs ac- aca acb acc ace acg aci acr acs aea aeb aec aee aeg aei aer aes ag- aga agb agc age agg agi agr ags ai- aia aib aic aie aig aii air ais ar- ara arb arc are arg ari arr ars as- asa asb asc ase asg asi asr ass baa bab bac bae bag bai bar bas bba bbb bbc bbe bbg bbi bbr bbs bca bcb bcc bce bcg bci bcr bcs be- bea beb bec bee beg bei ber bes bga bgb bgc bge bgg bgi bgr bgs bi- bia bib bic bie big bii bir bis bra brb bre brg bri brr brs bsa bsb bsc bse bsg bsi bsr bss c-- caa cab cac cae cag cai car cas cba cbb cbc cbe cbg cbi cbr cbs cca ccb ccc cce ccg cci ccr ccs ce- cea ceb cec cee ceg cei cer ces cga cgb cgc cge cgg cgi cgr cgs ci- cia cib cic cie cig cii cir cis cra crb crc cre crg cri crr crs csa csb csc cse csg csi csr css eaa eab eac eae eag eai ear eas eba ebb ebc ebe ebg ebi ebr ebs ec- eca ecb ecc ece ecg eci ecr ecs eea eeb eec eee eeg eer ees ega egb egc ege egg egi egr egs eia eib eic eie eig eii eir eis era erb erc ere erg eri err ers es- esa esb esc ese esg esi esr ess gaa gab gac gae gag gai gar gas gba gbc gbe gbg gbi gbr gbs gca gcb gcc gce gcg gci gcr gcs ge- gea geb gec gee geg gei ger ges gga ggb ggc ggg ggi ggr ggs gia gib gic gie gig gii gir gis gra grb grc gre grg gri grr grs gsa gsb gsc gse gsg gsi gsr gss ia- iaa iab iac iae iag iai iar ias iba ibb ibc ibe ibg ibi ibr ibs ica icb icc ice icg ici icr ics ie- iea iec iee ieg iei ier ies iga igb igc ige igg igi igr igs iia iib iic iie iii iir iis ir- ira irb irc ire irg iri irr irs is- isa isb isc ise isg isi isr iss ra- raa rab rac rae rag rai rar ras rba rbb rbc rbe rbg rbi rbr rbs rca rcb rcc rce rcg rci rcr rcs re- rea reb rec ree reg rei rer res rga rgb rgc rge rgg rgi rgr rgs ria rib ric rie rig rii rir ris rra rrb rrc rrg rri rrr rrs rsa rsb rsc rse rsg rsi rsr rss saa sab sac sae sag sai sar sas sba sbb sbc sbe sbg sbi sbr sbs sca scb scc sce scg sci scr scs se- sea seb sec see seg sei ser ses sga sgb sgc sge sgg sgi sgr sgs sia sib sic sie sig sii sir sis sr- sra srb src sre srg sri srr srs ss- ssa ssb ssc sse ssg ssi ssr sss