-er a-a a-b a-c aaa aab aac aae aaj aak aao aar ab- aba abb abc abe abj abk abo abr ac- aca acb acc ace acj ack aco acr aea aeb aec aee aej aek aeo aer aja ajb ajc aje ajj ajk ajo ajr aka akb akc ake akj akk ako akr aoa aob aoc aoe aoj aok aoo aor ar- ara arb arc are arj ark aro arr baa bab bac bae baj bak bao bar bba bbb bbc bbe bbk bbo bbr bca bcb bcc bce bcj bck bco bcr be- bea beb bec bee bek beo ber bja bjc bjj bjk bjr bka bkb bkc bke bkk bko bkr boa bob boc boe boj bok boo bor bra brb bre brj brk bro brr c-- c-j caa cab cac cae caj cak cao car cba cbb cbc cbe cbj cbk cbo cbr cca ccb ccc cce ccj cck cco ccr ce- cea ceb cec cee cej cek ceo cer cja cjb cjc cjk cjr cka ckb ckc cko co- coa cob coc coe coj cok coo cor cra crb crc cre crj crk cro crr eaa eab eac eae eaj eak eao ear eba ebb ebc ebe ebj ebk ebo ebr ec- eca ecb ecc ece ecj eck eco ecr eea eeb eec eee eek eeo eer eja ejc ejo eka ekb ekc eke eko ekr eo- eoa eob eoc eoe eok eoo eor era erb erc ere erk ero err jaa jab jac jae jaj jak jao jar 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 joa job joc joe joj jok joo jor jra jrb jrc jrk jro jrr ka- kaa kab kac kae kaj kak kao kar kba kbb kbc kbe kbk kbo kbr kca kcb kcc kce kck kcr ke- kea keb kec kee kek keo ker kjb kjc kje kjr kkb kkc kke kkk kkr koa kob koc koe kok koo kor kra krc krk kro krr oaa oab oac oae oaj oak oao oar ob- oba obb obc obe obj obk obo obr oc- oca ocb occ ocj ock oco ocr oea oeb oec oee oeo oer oja ojb ojc oje ojo oka okb okc oke okj okk oko okr oo- ooa oob ooc ook ooo oor or- ora orb orc ore ork oro orr ra- raa rab rac rae raj rak rao rar rba rbb rbc rbe rbk rbo rbr rca rcb rcc rce rcj rco rcr re- rea reb rec ree rek reo rer rja rjc rjk rjr rkb rkc rke rkk rko roa rob roc roe roj rok roo ror rra rrb rrc rrk rrr