-er a-a a-b a-c aaa aab aac aae aah aan aar ab- aba abb abc abe abh abn abr ac- aca acb acc ace ach acn acr aea aeb aec aee aeh aen aer aha ahb ahc ahe ahh ahn ahr an- ana anb anc ane anh ann anr ar- ara arb arc are arh arn arr baa bab bac bae bah ban bar bba bbb bbc bbe bbh bbn bbr bca bcb bcc bce bch bcn bcr be- bea beb bec bee beh ben ber bha bhb bhc bhe bhh bhr bna bnb bnc bne bnn bnr bra brb bre brh brn brr c-- caa cab cac cae cah can car cba cbb cbc cbe cbh cbn cbr cca ccb ccc cce cch ccn ccr ce- cea ceb cec cee ceh cen cer ch- cha chb chc che chh chn chr cn- cna cnb cnc cne cnh cnn cnr cra crb crc cre crh crn crr eaa eab eac eae eah ean ear eba ebb ebc ebe ebh ebn ebr ec- eca ecb ecc ece ech ecn ecr eea eeb eec eee een eer eha ehb ehc ehe ehh ehn ehr en- ena enb enc ene enh enn enr era erb erc ere erh ern err haa hab hac hae hah han har hba hbb hbc hbe hbh hbn hbr hca hcb hcc hce hch hcn hcr he- hea heb hec hee heh hen her hha hhb hhc hhe hhh hhn hhr hna hnb hnc hne hnh hnn hr- hra hrb hrc hre hrh hrn hrr naa nab nac nae nah nan nar nba nbb nbc nbe nbn nbr nca ncb ncc nce nch ncn ncr ne- nea neb nec nee neh nen ner nha nhb nhc nhe nhh nhn nhr nna nnb nnc nne nnh nnn nra nrb nrc nre nrn nrr ra- raa rab rac rae rah ran rar rba rbb rbc rbe rbh rbn rbr rca rcb rcc rce rch rcn rcr re- rea reb rec ree reh ren rer rh- rha rhb rhc rhe rhh rhn rhr rna rnb rnc rnh rnn rnr rra rrb rrc rrh rrn rrr