Here is the result of my dynamic-programmed cookie monster:

$ time ruby challenge.rb
ESSESSSSSSESSEESEEEEEE = 74

real  0m0.022s
user  0m0.012s
sys   0m0.008s 
(ibook G4)

$ wc -lc challenge.rb 
      50    1521 challenge.rb

Same path as in Robert's solution.

regards,
quentin