-er a-a a-b a-i aaa aab aad aae aai aar aas ab- aba abb abd abe abi abr abs ad- ada adb add ade adi adr ads aea aeb aed aee aei aer aes ai- aia aib aid aie aii air ais ar- ara arb ard are ari arr ars as- asa asb asd ase asi asr ass baa bab bad bae bai bar bas bba bbb bbd bbe bbi bbr bbs bda bdb bdd bde bdi bdr bds be- bea beb bed bee bei ber bes bi- bia bib bid bie bii bir bis bra brb brd bre bri brr brs bsa bsb bsd bse bsi bsr bss daa dab dad dae dai dar das dba dbb dbd dbe dbi dbr dbs dda ddb ddd dde ddi ddr dds de- dea deb ded dee dei der des di- dia dib did die dii dir dis dra drb drd dre dri drr drs dsa dsb dsd dse dsi dsr dss eaa eab ead eae eai ear eas eba ebb ebd ebe ebi ebr ebs ed- eda edb edd ede edi edr eds eea eeb eed eee eer ees eia eib eid eie eii eir eis era erb erd ere eri err ers es- esa esb esd ese esi esr ess i-d ia- iaa iab iad iae iai iar ias iba ibb ibd ibe ibi ibr ibs ida idb idd ide idi idr ids ie- iea ied iee iei ier ies iia iib iid iie iii iir iis ir- ira irb ird ire iri irr irs is- isa isb isd ise isi isr iss ra- raa rab rad rae rai rar ras rba rbb rbd rbe rbi rbr rbs rda rdb rdd rde rdi rdr rds re- rea reb red ree rei rer res ria rib rid rie rii rir ris rra rrb rrd rri rrr rrs rsa rsb rsd rse rsi rsr rss saa sab sad sae sai sar sas sba sbb sbd sbe sbi sbr sbs sda sdb sdd sde sdi sdr sds se- sea seb sed see sei ser ses sia sib sid sie sii sir sis sr- sra srb srd sre sri srr srs ss- ssa ssb ssd sse ssi ssr sss