c-- ccc ccd cce cck cco cct cdc cdd cde cdk cdo cdt ce- cec ced cee cek ceo cet ckc ckd cko ckt co- coc cod coe cok coo cot ctc ctd cte ctk cto ctt dcc dcd dce dck dco dct ddc ddd dde ddk ddo ddt de- dec ded dee dek deo det dkc dke dkk dko dkt doc dod doe dok doo dot dtc dtd dte dtk dto dtt ec- ecc ecd ece eck eco ect ed- edc edd ede edk edo edt eec eed eee eek eeo eet ekc ekd eke eko ekt eo- eoc eod eoe eok eoo eot etc etd ete etk eto ett k-t kcc kcd kce kck kct kdc kde kdk kdo kdt ke- kec ked kee kek keo ket kkc kke kkk kkt koc kod koe kok koo kot ktc kte ktk kto ktt oc- occ ocd ock oco oct odc odd ode odo odt oec oed oee oeo oet okc okd oke okk oko oo- ooc ood ook ooo oot ot- otc otd ote otk oto ott tcc tcd tce tck tco tct tdc tdd tde tdk tdo tdt te- tec ted tee tek teo tet tkc tke tkk tko tkt to- toc tod toe tok too tot ttc ttd tte ttk tto ttt