-er -ic a-a a-b a-c a-i a-t aaa aab aac aae aai aar aat ab- aba abb abc abe abi abr abt ac- aca acb acc ace aci acr act aea aeb aec aee aei aer aet ai- aia aib aic aie aii air ait ar- ara arb arc are ari arr art at- ata atb atc ate ati atr att baa bab bac bae bai bar bat bba bbb bbc bbe bbi bbr bbt bca bcb bcc bce bci bcr bct be- bea beb bec bee bei ber bet bi- bia bib bic bie bii bir bit bra brb bre bri brr brt bta btb btc bte bti btr btt c-- caa cab cac cae cai car cat cba cbb cbc cbe cbi cbr cbt cca ccb ccc cce cci ccr cct ce- cea ceb cec cee cei cer cet ci- cia cib cic cie cii cir cit cra crb crc cre cri crr crt cta ctb ctc cte cti ctr ctt eaa eab eac eae eai ear eat eba ebb ebc ebe ebi ebr ebt ec- eca ecb ecc ece eci ecr ect eea eeb eec eee eer eet eia eib eic eie eii eir eit era erb erc ere eri err ert eta etb etc ete eti etr ett ia- iaa iab iac iae iai iar iat iba ibb ibc ibe ibi ibr ibt ica icb icc ice ici icr ict ie- iea iec iee iei ier iet iia iib iic iie iii iir iit ir- ira irb irc ire iri irr irt ita itb itc ite iti itt ra- raa rab rac rae rai rar rat rba rbb rbc rbe rbi rbr rbt rca rcb rcc rce rci rcr rct re- rea reb rec ree rei rer ret ria rib ric rie rii rir rit rra rrb rrc rri rrr rrt rta rtb rtc rte rti rtr rtt taa tab tac tae tai tar tat tba tbb tbc tbe tbi tbr tbt tca tcb tcc tce tci tcr tct te- tea teb tec tee tei ter tet tia tib tic tie tii tir tit tra trb trc tre tri trr trt tta ttb ttc tte tti ttr ttt