-er -ic a-a a-b a-c a-i a-t aaa aab aac aae aag aai aar aat ab- aba abb abc abe abg abi abr abt ac- aca acb acc ace acg aci acr act aea aeb aec aee aeg aei aer aet ag- aga agb agc age agg agi agr agt ai- aia aib aic aie aig aii air ait ar- ara arb arc are arg ari arr art at- ata atb atc ate atg ati atr att baa bab bac bae bag bai bar bat bba bbb bbc bbe bbg bbi bbr bbt bca bcb bcc bce bcg bci bcr bct be- bea beb bec bee beg bei ber bet bga bgb bgc bge bgg bgi bgr bgt bi- bia bib bic bie big bii bir bit bra brb bre brg bri brr brt bta btb btc bte btg bti btr btt c-- caa cab cac cae cag cai car cat cba cbb cbc cbe cbg cbi cbr cbt cca ccb ccc cce ccg cci ccr cct ce- cea ceb cec cee ceg cei cer cet cga cgb cgc cge cgg cgi cgr cgt ci- cia cib cic cie cig cii cir cit cra crb crc cre crg cri crr crt cta ctb ctc cte ctg cti ctr ctt eaa eab eac eae eag eai ear eat eba ebb ebc ebe ebg ebi ebr ebt ec- eca ecb ecc ece ecg eci ecr ect eea eeb eec eee eeg eer eet ega egb egc ege egg egi egr egt eia eib eic eie eig eii eir eit era erb erc ere erg eri err ert eta etb etc ete etg eti etr ett gaa gab gac gae gag gai gar gat gba gbc gbe gbg gbi gbr gbt gca gcb gcc gce gcg gci gcr gct ge- gea geb gec gee geg gei ger get gga ggb ggc ggg ggi ggr ggt gia gib gic gie gig gii gir git gra grb grc gre grg gri grr grt gta gtb gtc gte gtg gti gtr gtt ia- iaa iab iac iae iag iai iar iat iba ibb ibc ibe ibg ibi ibr ibt ica icb icc ice icg ici icr ict ie- iea iec iee ieg iei ier iet iga igb igc ige igg igi igr igt iia iib iic iie iii iir iit ir- ira irb irc ire irg iri irr irt ita itb itc ite itg iti itt ra- raa rab rac rae rag rai rar rat rba rbb rbc rbe rbg rbi rbr rbt rca rcb rcc rce rcg rci rcr rct re- rea reb rec ree reg rei rer ret rga rgb rgc rge rgg rgi rgr rgt ria rib ric rie rig rii rir rit rra rrb rrc rrg rri rrr rrt rta rtb rtc rte rtg rti rtr rtt taa tab tac tae tag tai tar tat tba tbb tbc tbe tbg tbi tbr tbt tca tcb tcc tce tcg tci tcr tct te- tea teb tec tee teg tei ter tet tga tgb tgc tge tgg tgi tgr tgt tia tib tic tie tig tii tir tit tra trb trc tre trg tri trr trt tta ttb ttc tte ttg tti ttr ttt