-er a-a a-b a-c aaa aab aac aad aae aan aar ab- aba abb abc abd abe abn abr ac- aca acb acc acd ace acn acr ad- ada adb adc add ade adn adr aea aeb aec aed aee aen aer an- ana anb anc and ane ann anr ar- ara arb arc ard are arn arr baa bab bac bad bae ban bar bba bbb bbc bbd bbe bbn bbr bca bcb bcc bcd bce bcn bcr bda bdb bdc bdd bde bdr be- bea beb bec bed bee ben ber bna bnb bnc bnd bne bnn bnr bra brb brd bre brn brr c-- caa cab cac cad cae can car cba cbb cbc cbd cbe cbn cbr cca ccb ccc ccd cce ccn ccr cda cdb cdc cdd cde cdn cdr ce- cea ceb cec ced cee cen cer cn- cna cnb cnc cnd cne cnn cnr cra crb crc crd cre crn crr daa dab dac dad dae dan dar dba dbb dbc dbd dbe dbn dbr dca dcb dcc dcd dce dcn dcr dda ddb ddc ddd dde ddn ddr de- dea deb dec ded dee den der dna dnb dnc dnd dne dnn dnr dra drb drc drd dre drn drr eaa eab eac ead eae ean ear eba ebb ebc ebd ebe ebn ebr ec- eca ecb ecc ecd ece ecn ecr ed- eda edb edc edd ede edn edr eea eeb eec eed eee een eer en- ena enb enc end ene enn enr era erb erc erd ere ern err naa nab nac nad nae nan nar nba nbb nbc nbd nbe nbn nbr nca ncb ncc ncd nce ncn ncr nda ndb ndc ndd nde ndn ndr ne- nea neb nec ned nee nen ner nna nnb nnc nne nnn nra nrb nrc nrd nre nrn nrr ra- raa rab rac rad rae ran rar rba rbb rbc rbd rbe rbn rbr rca rcb rcc rcd rce rcn rcr rda rdb rdc rdd rde rdn rdr re- rea reb rec red ree ren rer rna rnb rnc rnd rnn rnr rra rrb rrc rrd rrn rrr