-er a-a a-b a-c aaa aab aac aae aah aak aan aar ab- aba abb abc abe abh abk abn abr ac- aca acb acc ace ach ack acn acr aea aeb aec aee aeh aek aen aer aha ahb ahc ahe ahh ahk ahn ahr aka akb akc ake akh akk akn akr an- ana anb anc ane anh ank ann anr ar- ara arb arc are arh ark arn arr baa bab bac bae bah bak ban bar bba bbb bbc bbe bbh bbk bbn bbr bca bcb bcc bce bch bck bcn bcr be- bea beb bec bee beh bek ben ber bha bhb bhc bhe bhh bhk bhr bka bkb bkc bke bkk bkn bkr bna bnb bnc bne bnk bnn bnr bra brb bre brh brk brn brr c-- caa cab cac cae cah cak can car cba cbb cbc cbe cbh cbk cbn cbr cca ccb ccc cce cch cck ccn ccr ce- cea ceb cec cee ceh cek cen cer ch- cha chb chc che chh chk chn chr cka ckb ckc ckh cn- cna cnb cnc cne cnh cnn cnr cra crb crc cre crh crk crn crr eaa eab eac eae eah eak ean ear eba ebb ebc ebe ebh ebk ebn ebr ec- eca ecb ecc ece ech eck ecn ecr eea eeb eec eee eek een eer eha ehb ehc ehe ehh ehn ehr eka ekb ekc eke ekh ekr en- ena enb enc ene enh enk enn enr era erb erc ere erh erk ern err haa hab hac hae hah hak han har hba hbb hbc hbe hbh hbk hbn hbr hca hcb hcc hce hch hck hcn hcr he- hea heb hec hee heh hek hen her hha hhb hhc hhe hhh hhk hhn hhr hka hkb hkh hkk hkn hkr hna hnb hnc hne hnh hnk hnn hr- hra hrb hrc hre hrh hrk hrn hrr ka- kaa kab kac kae kah kak kan kar kba kbb kbc kbe kbh kbk kbn kbr kca kcb kcc kce kch kck kcn kcr ke- kea keb kec kee keh kek ken ker kha khe khh khk khn khr kkb kkc kke kkh kkk kkn kkr kn- kna knc kne knk knn knr kra krc krk krn krr naa nab nac nae nah nak nan nar nba nbb nbc nbe nbk nbn nbr nca ncb ncc nce nch nck ncn ncr ne- nea neb nec nee neh nek nen ner nha nhb nhc nhe nhh nhk nhn nhr nka nkc nke nkk nkn nkr nna nnb nnc nne nnh nnk nnn nra nrb nrc nre nrk nrn nrr ra- raa rab rac rae rah rak ran rar rba rbb rbc rbe rbh rbk rbn rbr rca rcb rcc rce rch rcn rcr re- rea reb rec ree reh rek ren rer rh- rha rhb rhc rhe rhh rhn rhr rkb rkc rke rkk rna rnb rnc rnh rnn rnr rra rrb rrc rrh rrk rrn rrr