Rukkuea #68
Color the cells of the grid black or white to form squares of black cells. The squares must not touch each other orthogonally, but diagonally.
Squares of the same size must not "see" each other, i.e., in the horizontal and vertical lines of sight, there must always be a square of a different size between them.
A numbered cell together with it's orthogonal neighbors defines a "cross" that consists of the cell and it's up to four orthogonal neighbors. The number indicates how many of these neighboring cells should be blackened.