-er a-a a-b a-c a-t a-z aaa aab aac aae aao aar aat aaz ab- aba abb abc abe abo abr abt abz ac- aca acb acc ace aco acr act acz aea aeb aec aee aeo aer aet aez aoa aob aoc aoe aoo aor aot ar- ara arb arc are aro arr art arz at- ata atb atc ate ato atr att atz az- aza azb aze azo azt azz baa bab bac bae bao bar bat baz bba bbb bbc bbe bbo bbr bbt bca bcb bcc bce bco bcr bct bcz be- bea beb bec bee beo ber bet bez boa bob boc boe boo bor bot boz bra brb bre bro brr brt brz bta btb btc bte bto btr btt btz bza bze bzo bzr bzz c-- caa cab cac cae cao car cat caz cba cbb cbc cbe cbo cbr cbt cbz cca ccb ccc cce cco ccr cct ccz ce- cea ceb cec cee ceo cer cet cez co- coa cob coc coe coo cor cot coz cra crb crc cre cro crr crt crz cta ctb ctc cte cto ctr ctt ctz cz- czc cze czo czt eaa eab eac eae eao ear eat eaz eba ebb ebc ebe ebo ebr ebt ec- eca ecb ecc ece eco ecr ect eea eeb eec eee eeo eer eet eo- eoa eob eoc eoe eoo eor eot era erb erc ere ero err ert erz eta etb etc ete eto etr ett etz eze ezo ezr ezz oaa oab oac oae oao oar oat ob- oba obb obc obe obo obr obt oc- oca ocb occ oco ocr oct ocz oea oeb oec oee oeo oer oet oo- ooa oob ooc ooo oor oot or- ora orb orc ore oro orr ort orz ot- ota otb otc ote oto otr ott otz oza oze ozo ozt ozz ra- raa rab rac rae rao rar rat raz rba rbb rbc rbe rbo rbr rbt rca rcb rcc rce rco rcr rct re- rea reb rec ree reo rer ret rez roa rob roc roe roo ror rot roz rra rrb rrc rrr rrt rta rtb rtc rte rto rtr rtt rtz rza rzb rze rzo taa tab tac tae tao tar tat taz tba tbb tbc tbe tbo tbr tbt tbz tca tcb tcc tce tco tcr tct te- tea teb tec tee teo ter tet tez to- toa tob toc toe too tor tot toz tra trb trc tre tro trr trt trz tta ttb ttc tte tto ttr ttt tza tze zaa zab zac zao zar zat zaz zbb zbc zbr zbt zce zco zea zeb zec zee zeo zer zet zez zo- zoa zob zoc zoe zoo zor zot zro zta zte ztr zzr zzt zzz