-er a-a a-b a-c a-z aaa aab aac aae aak aar aaz ab- aba abb abc abe abk abr abz ac- aca acb acc ace ack acr acz aea aeb aec aee aek aer aez aka akb akc ake akk akr ar- ara arb arc are ark arr arz az- aza azb aze azz baa bab bac bae bak bar baz bba bbb bbc bbe bbk bbr bca bcb bcc bce bck bcr bcz be- bea beb bec bee bek ber bez bka bkb bkc bke bkk bkr bra brb bre brk brr brz bza bze bzr bzz c-- caa cab cac cae cak car caz cba cbb cbc cbe cbk cbr cbz cca ccb ccc cce cck ccr ccz ce- cea ceb cec cee cek cer cez cka ckb ckc cra crb crc cre crk crr crz cz- czc cze czk eaa eab eac eae eak ear eaz eba ebb ebc ebe ebk ebr ec- eca ecb ecc ece eck ecr eea eeb eec eee eek eer eka ekb ekc eke ekr era erb erc ere erk err erz eze ezr ezz k-z ka- kaa kab kac kae kak kar kaz kba kbb kbc kbe kbk kbr kbz kca kcb kcc kce kck kcr ke- kea keb kec kee kek ker kez kkb kkc kke kkk kkr kra krc krk krr ra- raa rab rac rae rak rar raz rba rbb rbc rbe rbk rbr rca rcb rcc rce rcr re- rea reb rec ree rek rer rez rkb rkc rke rkk rkz rra rrb rrc rrk rrr rza rzb rze zaa zab zac zak zar zaz zbb zbc zbr zce zea zeb zec zee zek zer zez zka zzr zzz