-er a-a a-b a-c aaa aab aac aad aae aah aao aar ab- aba abb abc abd abe abh abo abr ac- aca acb acc acd ace ach aco acr ad- ada adb adc add ade adh ado adr aea aeb aec aed aee aeh aeo aer aha ahb ahc ahd ahe ahh aho ahr aoa aob aoc aod aoe aoh aoo aor ar- ara arb arc ard are arh aro arr baa bab bac bad bae bah bao bar bba bbb bbc bbd bbe bbh bbo bbr bca bcb bcc bcd bce bch bco bcr bda bdb bdc bdd bde bdh bdo bdr be- bea beb bec bed bee beh beo ber bha bhb bhc bhd bhe bhh bho bhr boa bob boc bod boe boh boo bor bra brb brd bre brh bro brr c-- caa cab cac cad cae cah cao car cba cbb cbc cbd cbe cbh cbo cbr cca ccb ccc ccd cce cch cco ccr cda cdb cdc cdd cde cdh cdo cdr ce- cea ceb cec ced cee ceh ceo cer ch- cha chb chc chd che chh cho chr co- coa cob coc cod coe coh coo cor cra crb crc crd cre crh cro crr daa dab dac dad dae dah dao dar dba dbb dbc dbd dbe dbh dbo dbr dca dcb dcc dcd dce dco dcr dda ddb ddc ddd dde ddh ddo ddr de- dea deb dec ded dee deh deo der dh- dha dhb dhc dhd dhe dhh dho dhr doa dob doc dod doe doh doo dor dra drb drc drd dre dro drr eaa eab eac ead eae eah eao ear eba ebb ebc ebd ebe ebh ebo ebr ec- eca ecb ecc ecd ece ech eco ecr ed- eda edb edc edd ede edh edo edr eea eeb eec eed eee eeo eer eha ehb ehc ehd ehe ehh eho ehr eo- eoa eob eoc eod eoe eoh eoo eor era erb erc erd ere erh ero err haa hab hac had hae hah hao har hba hbb hbc hbd hbe hbh hbo hbr hca hcb hcc hcd hce hch hco hcr hda hdb hdc hdd hde hdh hdo hdr he- hea heb hec hed hee heh heo her hha hhb hhc hhd hhe hhh hho hhr hoa hob hoc hod hoe hoh hoo hor hr- hra hrb hrc hrd hre hrh hro hrr oaa oab oac oad oae oah oao oar ob- oba obb obc obd obe obh obo obr oc- oca ocb occ ocd och 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 oo- ooa oob ooc ood ooh ooo oor or- ora orb orc ord ore orh oro orr ra- raa rab rac rad rae rah rao rar rba rbb rbc rbd rbe rbh 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 reo rer rh- rha rhb rhc rhd rhe rhh rho rhr roa rob roc rod roe roh roo ror rra rrb rrc rrd rrh rrr