-er a-a a-b a-c aaa aab aac aad aae aah aar ab- aba abb abc abd abe abh abr ac- aca acb acc acd ace ach acr ad- ada adb adc add ade adh adr aea aeb aec aed aee aeh aer aha ahb ahc ahd ahe ahh ahr ar- ara arb arc ard are arh arr baa bab bac bad bae bah bar bba bbb bbc bbd bbe bbh bbr bca bcb bcc bcd bce bch bcr bda bdb bdc bdd bde bdh bdr be- bea beb bec bed bee beh ber bha bhb bhc bhd bhe bhh bhr bra brb brd bre brh brr c-- caa cab cac cad cae cah car cba cbb cbc cbd cbe cbh cbr cca ccb ccc ccd cce cch ccr cda cdb cdc cdd cde cdh cdr ce- cea ceb cec ced cee ceh cer ch- cha chb chc chd che chh chr cra crb crc crd cre crh crr daa dab dac dad dae dah dar dba dbb dbc dbd dbe dbh dbr dca dcb dcc dcd dce dcr dda ddb ddc ddd dde ddh ddr de- dea deb dec ded dee deh der dh- dha dhb dhc dhd dhe dhh dhr dra drb drc drd dre drr eaa eab eac ead eae eah ear eba ebb ebc ebd ebe ebh ebr ec- eca ecb ecc ecd ece ech ecr ed- eda edb edc edd ede edh edr eea eeb eec eed eee eer eha ehb ehc ehd ehe ehh ehr era erb erc erd ere erh err haa hab hac had hae hah har hba hbb hbc hbd hbe hbh hbr hca hcb hcc hcd hce hch hcr hda hdb hdc hdd hde hdh hdr he- hea heb hec hed hee heh her hha hhb hhc hhd hhe hhh hhr hr- hra hrb hrc hrd hre hrh hrr ra- raa rab rac rad rae rah rar rba rbb rbc rbd rbe rbh rbr rca rcb rcc rcd rce rch rcr rda rdb rdc rdd rde rdh rdr re- rea reb rec red ree reh rer rh- rha rhb rhc rhd rhe rhh rhr rra rrb rrc rrd rrh rrr