-er a-a a-b a-c aaa aab aac aad aae aah aak aao aar ab- aba abb abc abd abe abh abk abo abr ac- aca acb acc acd ace ach ack aco acr ad- ada adb adc add ade adh adk ado adr aea aeb aec aed aee aeh aek aeo aer aha ahb ahc ahd ahe ahh ahk aho ahr aka akb akc akd ake akh akk ako akr aoa aob aoc aod aoe aoh aok aoo aor ar- ara arb arc ard are arh ark aro arr baa bab bac bad bae bah bak bao bar bba bbb bbc bbd bbe bbh bbk bbo bbr bca bcb bcc bcd bce bch bck bco bcr bda bdb bdc bdd bde bdh bdk bdo bdr be- bea beb bec bed bee beh bek beo ber bha bhb bhc bhd bhe bhh bhk bho bhr bka bkb bkc bke bkk bko bkr boa bob boc bod boe boh bok boo bor bra brb brd bre brh brk bro brr c-- caa cab cac cad cae cah cak cao car cba cbb cbc cbd cbe cbh cbk cbo cbr cca ccb ccc ccd cce cch cck cco ccr cda cdb cdc cdd cde cdh cdk cdo cdr ce- cea ceb cec ced cee ceh cek ceo cer ch- cha chb chc chd che chh chk cho chr cka ckb ckc ckd ckh cko co- coa cob coc cod coe coh cok coo cor cra crb crc crd cre crh crk cro crr daa dab dac dad dae dah dak dao dar dba dbb dbc dbd dbe dbh dbk dbo dbr dca dcb dcc dcd dce dck dco dcr dda ddb ddc ddd dde ddh ddk ddo ddr de- dea deb dec ded dee deh dek deo der dh- dha dhb dhc dhd dhe dhh dhk dho dhr dka dkb dkc dke dkk dko dkr doa dob doc dod doe doh dok doo dor dra drb drc drd dre drk dro drr eaa eab eac ead eae eah eak eao ear eba ebb ebc ebd ebe ebh ebk ebo ebr ec- eca ecb ecc ecd ece ech eck eco ecr ed- eda edb edc edd ede edh edk edo edr eea eeb eec eed eee eek eeo eer eha ehb ehc ehd ehe ehh eho ehr eka ekb ekc ekd eke ekh eko ekr eo- eoa eob eoc eod eoe eoh eok eoo eor era erb erc erd ere erh erk ero err haa hab hac had hae hah hak hao har hba hbb hbc hbd hbe hbh hbk hbo hbr hca hcb hcc hcd hce hch hck hco hcr hda hdb hdc hdd hde hdh hdk hdo hdr he- hea heb hec hed hee heh hek heo her hha hhb hhc hhd hhe hhh hhk hho hhr hka hkb hkd hkh hkk hko hkr hoa hob hoc hod hoe hoh hok hoo hor hr- hra hrb hrc hrd hre hrh hrk hro hrr ka- kaa kab kac kad kae kah kak kao kar kba kbb kbc kbd kbe kbh kbk kbo kbr kca kcb kcc kcd kce kch kck kcr kda kdb kdc kde kdh kdk kdo kdr ke- kea keb kec ked kee keh kek keo ker kha khe khh khk kho khr kkb kkc kke kkh kkk kkr koa kob koc kod koe koh kok koo kor kra krc krd krk kro krr oaa oab oac oad oae oah oak oao oar ob- oba obb obc obd obe obh obk obo obr oc- oca ocb occ ocd och ock oco ocr oda odb odc odd ode odh odo odr oea oeb oec oed oee oeh oeo oer oha ohc ohd ohe ohh oho ohr oka okb okc okd oke okk oko okr oo- ooa oob ooc ood ooh ook ooo oor or- ora orb orc ord ore orh ork oro orr ra- raa rab rac rad rae rah rak rao rar rba rbb rbc rbd rbe rbh rbk rbo rbr rca rcb rcc rcd rce rch rco rcr rda rdb rdc rdd rde rdh rdo rdr re- rea reb rec red ree reh rek reo rer rh- rha rhb rhc rhd rhe rhh rho rhr rkb rkc rke rkk rko roa rob roc rod roe roh rok roo ror rra rrb rrc rrd rrh rrk rrr