-er a-a a-b a-c a-t a-z aaa aab aac aae aar aat aaz ab- aba abb abc abe abr abt abz ac- aca acb acc ace acr act acz aea aeb aec aee aer aet aez ar- ara arb arc are arr art arz at- ata atb atc ate atr att atz az- aza azb aze azt azz baa bab bac bae bar bat baz bba bbb bbc bbe bbr bbt bca bcb bcc bce bcr bct bcz be- bea beb bec bee ber bet bez bra brb bre brr brt brz bta btb btc bte btr btt btz bza bze bzr bzz c-- caa cab cac cae car cat caz cba cbb cbc cbe cbr cbt cbz cca ccb ccc cce ccr cct ccz ce- cea ceb cec cee cer cet cez cra crb crc cre crr crt crz cta ctb ctc cte ctr ctt ctz cz- czc cze czt eaa eab eac eae ear eat eaz eba ebb ebc ebe ebr ebt ec- eca ecb ecc ece ecr ect eea eeb eec eee eer eet era erb erc ere err ert erz eta etb etc ete etr ett etz eze ezr ezz ra- raa rab rac rae rar rat raz rba rbb rbc rbe rbr rbt rca rcb rcc rce rcr rct re- rea reb rec ree rer ret rez rra rrb rrc rrr rrt rta rtb rtc rte rtr rtt rtz rza rzb rze taa tab tac tae tar tat taz tba tbb tbc tbe tbr tbt tbz tca tcb tcc tce tcr tct te- tea teb tec tee ter tet tez tra trb trc tre trr trt trz tta ttb ttc tte ttr ttt tza tze zaa zab zac zar zat zaz zbb zbc zbr zbt zce zea zeb zec zee zer zet zez zta zte ztr zzr zzt zzz