c-- ccc cce ccf cco cct ce- cec cee cef ceo cet cfc cfe cff cfo cft co- coc coe cof coo cot ctc cte ctf cto ctt ec- ecc ece ecf eco ect eec eee eef eeo eet ef- efc efe eff efo eft eo- eoc eoe eof eoo eot etc ete etf eto ett fcc fce fcf fco fct fec fee fef feo fet ffc ffe fff ffo fft foc foe fof foo fot ftc fte ftf fto ftt oc- occ ocf oco oct oec oee oef oeo oet of- ofc ofe off ofo oft oo- ooc oof ooo oot ot- otc ote otf oto ott tcc tce tcf tco tct te- tec tee tef teo tet tfc tfe tff tfo tft to- toc toe tof too tot ttc tte ttf tto ttt