-er a-a a-b a-c aaa aab aac aae aah aar ab- aba abb abc abe abh abr ac- aca acb acc ace ach acr aea aeb aec aee aeh aer aha ahb ahc ahe ahh ahr ar- ara arb arc are arh arr baa bab bac bae bah bar bba bbb bbc bbe bbh bbr bca bcb bcc bce bch bcr be- bea beb bec bee beh ber bha bhb bhc bhe bhh bhr bra brb bre brh brr c-- caa cab cac cae cah car cba cbb cbc cbe cbh cbr cca ccb ccc cce cch ccr ce- cea ceb cec cee ceh cer ch- cha chb chc che chh chr cra crb crc cre crh crr eaa eab eac eae eah ear eba ebb ebc ebe ebh ebr ec- eca ecb ecc ece ech ecr eea eeb eec eee eer eha ehb ehc ehe ehh ehr era erb erc ere erh err haa hab hac hae hah har hba hbb hbc hbe hbh hbr hca hcb hcc hce hch hcr he- hea heb hec hee heh her hha hhb hhc hhe hhh hhr hr- hra hrb hrc hre hrh hrr ra- raa rab rac rae rah rar rba rbb rbc rbe rbh rbr rca rcb rcc rce rch rcr re- rea reb rec ree reh rer rh- rha rhb rhc rhe rhh rhr rra rrb rrc rrh rrr