-er a-a a-b a-t a-z aaa aab aae aak aao aar aat aaz ab- aba abb abe abk abo abr abt abz aea aeb aee aek aeo aer aet aez aka akb ake akk ako akr aoa aob aoe aok aoo aor aot ar- ara arb are ark aro arr art arz at- ata atb ate ato atr att atz az- aza azb aze azo azt azz baa bab bae bak bao bar bat baz bba bbb bbe bbk bbo bbr bbt be- bea beb bee bek beo ber bet bez bka bkb bke bkk bko bkr bkt boa bob boe bok boo bor bot boz bra brb bre brk bro brr brt brz bta btb bte btk bto btr btt btz bza bze bzo bzr bzz eaa eab eae eak eao ear eat eaz eba ebb ebe ebk ebo ebr ebt eea eeb eee eek eeo eer eet eka ekb eke eko ekr ekt eo- eoa eob eoe eok eoo eor eot era erb ere erk ero err ert erz eta etb ete etk eto etr ett etz eze ezo ezr ezz k-t k-z ka- kaa kab kae kak kao kar kat kaz kba kbb kbe kbk kbo kbr kbz ke- kea keb kee kek keo ker ket kez kkb kke kkk kkr kkt koa kob koe kok koo kor kot koz kra krk kro krr krt kta ktb kte ktk kto ktr ktt kzo oaa oab oae oak oao oar oat ob- oba obb obe obk obo obr obt oea oeb oee oeo oer oet oka okb oke okk oko okr oo- ooa oob ook ooo oor oot or- ora orb ore ork oro orr ort orz ot- ota otb ote otk oto otr ott otz oza oze ozo ozt ozz ra- raa rab rae rak rao rar rat raz rba rbb rbe rbk rbo rbr rbt re- rea reb ree rek reo rer ret rez rkb rke rkk rko rkt rkz roa rob roe rok roo ror rot roz rra rrb rrk rrr rrt rta rtb rte rtk rto rtr rtt rtz rza rzb rze rzo taa tab tae tak tao tar tat taz tba tbb tbe tbk tbo tbr tbt tbz te- tea teb tee tek teo ter tet tez tka tkb tke tkk tko tkr tkt tkz to- toa tob toe tok too tor tot toz tra trb tre trk tro trr trt trz tta ttb tte ttk tto ttr ttt tza tze zaa zab zak zao zar zat zaz zbb zbr zbt zea zeb zee zek zeo zer zet zez zka zo- zoa zob zoe zok zoo zor zot zro zta zte ztr zzr zzt zzz