-er a-a a-b a-c aaa aab aac aae aah aak aar ab- aba abb abc abe abh abk abr ac- aca acb acc ace ach ack acr aea aeb aec aee aeh aek aer aha ahb ahc ahe ahh ahk ahr aka akb akc ake akh akk akr ar- ara arb arc are arh ark arr baa bab bac bae bah bak bar bba bbb bbc bbe bbh bbk bbr bca bcb bcc bce bch bck bcr be- bea beb bec bee beh bek ber bha bhb bhc bhe bhh bhk bhr bka bkb bkc bke bkk bkr bra brb bre brh brk brr c-- caa cab cac cae cah cak car cba cbb cbc cbe cbh cbk cbr cca ccb ccc cce cch cck ccr ce- cea ceb cec cee ceh cek cer ch- cha chb chc che chh chk chr cka ckb ckc ckh cra crb crc cre crh crk crr eaa eab eac eae eah eak ear eba ebb ebc ebe ebh ebk ebr ec- eca ecb ecc ece ech eck ecr eea eeb eec eee eek eer eha ehb ehc ehe ehh ehr eka ekb ekc eke ekh ekr era erb erc ere erh erk err haa hab hac hae hah hak har hba hbb hbc hbe hbh hbk hbr hca hcb hcc hce hch hck hcr he- hea heb hec hee heh hek her hha hhb hhc hhe hhh hhk hhr hka hkb hkh hkk hkr hr- hra hrb hrc hre hrh hrk hrr ka- kaa kab kac kae kah kak kar kba kbb kbc kbe kbh kbk kbr kca kcb kcc kce kch kck kcr ke- kea keb kec kee keh kek ker kha khe khh khk khr kkb kkc kke kkh kkk kkr kra krc krk krr ra- raa rab rac rae rah rak rar rba rbb rbc rbe rbh rbk rbr rca rcb rcc rce rch rcr re- rea reb rec ree reh rek rer rh- rha rhb rhc rhe rhh rhr rkb rkc rke rkk rra rrb rrc rrh rrk rrr