a-a a-b a-c aaa aab aac aad aae aao ab- aba abb abc abd abe abo ac- aca acb acc acd ace aco ad- ada adb adc add ade ado aea aeb aec aed aee aeo aoa aob aoc aod aoe aoo baa bab bac bad bae bao bba bbb bbc bbd bbe bbo bca bcb bcc bcd bce bco bda bdb bdc bdd bde bdo be- bea beb bec bed bee beo boa bob boc bod boe boo c-- caa cab cac cad cae cao cba cbb cbc cbd cbe cbo cca ccb ccc ccd cce cco cda cdb cdc cdd cde cdo ce- cea ceb cec ced cee ceo co- coa cob coc cod coe coo daa dab dac dad dae dao dba dbb dbc dbd dbe dbo dca dcb dcc dcd dce dco dda ddb ddc ddd dde ddo de- dea deb dec ded dee deo doa dob doc dod doe doo eaa eab eac ead eae eao eba ebb ebc ebd ebe ebo ec- eca ecb ecc ecd ece eco ed- eda edb edc edd ede edo eea eeb eec eed eee eeo eo- eoa eob eoc eod eoe eoo oaa oab oac oad oae oao ob- oba obb obc obd obe obo oc- oca ocb occ ocd oco oda odb odc odd ode odo oea oeb oec oed oee oeo oo- ooa oob ooc ood ooo