MathDB

A coloring of all plane points with coordinates belonging to the set

S=\{0,1,\ldots,99\}

into red and white colors is said to be critical if for each

i,j\in S

at least one of the four points

(i,j),(i + 1,j),(i,j + 1)

and

(i + 1, j + 1)

(99 + 1\equiv0)

is colored red. Find the maximal possible number of red points in a critical coloring which loses its property after recoloring of any red point into white.

Problem Statement