Each of the things in square brackets is a little
paint-by-number. For example, [R=(3),C=(1,1,1)] gives
. Each of these "odd
staircases" is a chomp
board; using the mex rule, you can evaluate each board's nimber, and these gives
rows and columns for a new paint-by-number:

When filled in, this gives

giving the answer CEASAR.