-er a-a a-b a-c aaa aab aac aae aaj aak aao aar aax ab- aba abb abc abe abj abk abo abr abx ac- aca acb acc ace acj ack aco acr acx aea aeb aec aee aej aek aeo aer aex aja ajb ajc aje ajj ajk ajo ajr aka akb akc ake akj akk ako akr aoa aob aoc aoe aoj aok aoo aor aox ar- ara arb arc are arj ark aro arr arx ax- axa axe axj axk axo axr axx baa bab bac bae baj bak bao bar bax bba bbb bbc bbe bbk bbo bbr bbx bca bcb bcc bce bcj bck bco bcr bcx be- bea beb bec bee bek beo ber bex bja bjc bjj bjk bjr bka bkb bkc bke bkk bko bkr bkx boa bob boc boe boj bok boo bor box bra brb bre brj brk bro brr brx bxb bxj bxo bxx c-- c-j caa cab cac cae caj cak cao car cax cba cbb cbc cbe cbj cbk cbo cbr cbx cca ccb ccc cce ccj cck cco ccr ccx ce- cea ceb cec cee cej cek ceo cer cex cja cjb cjc cjk cjr cka ckb ckc cko ckx co- coa cob coc coe coj cok coo cor cox cra crb crc cre crj crk cro crr crx cxc cxj cxk cxo cxr cxx eaa eab eac eae eaj eak eao ear eax eba ebb ebc ebe ebj ebk ebo ebr ebx ec- eca ecb ecc ece ecj eck eco ecr ecx eea eeb eec eee eek eeo eer eex eja ejc ejo eka ekb ekc eke eko ekr eo- eoa eob eoc eoe eok eoo eor era erb erc ere erk ero err ex- exa exc exe exo exr exx jaa jab jac jae jaj jak jao jar jax jba jbc jbj jbk jbo jbr jca jcb jcc jce jck jco jcr jea jeb jec jee jej jek jeo jer jja jjb jjc jjj jjk jjr jka jkb jkk jko jkr jkx joa job joc joe joj jok joo jor jra jrb jrc jrk jro jrr ka- kaa kab kac kae kaj kak kao kar kax kba kbb kbc kbe kbk kbo kbr kbx kca kcb kcc kce kck kcr kcx ke- kea keb kec kee kek keo ker kex kjb kjc kje kjr kkb kkc kke kkk kkr koa kob koc koe kok koo kor kra krc krk kro krr kxo oaa oab oac oae oaj oak oao oar oax ob- oba obb obc obe obj obk obo obr obx oc- oca ocb occ ocj ock oco ocr ocx oea oeb oec oee oeo oer oex oja ojb ojc oje ojo oka okb okc oke okj okk oko okr oo- ooa oob ooc ook ooo oor oox or- ora orb orc ore ork oro orr orx ox- oxa oxb oxc oxo oxx ra- raa rab rac rae raj rak rao rar rax rba rbb rbc rbe rbk rbo rbr rbx rca rcb rcc rce rcj rco rcr rcx re- rea reb rec ree rek reo rer rex rja rjc rjk rjr rkb rkc rke rkk rko roa rob roc roe roj rok roo ror rox rra rrb rrc rrk rrr rxr xaa xac xak xar xbc xbe xbr xbx xcb xcr xcx xee xer xex xjo xkb xke xoa xoc xok xoo xor xox xrc xrx xxo xxx