Fill the grid with the digits 1-9. Each row N and column N contain exactly N distinct digits, with the rest of the row / column being filled with repeats. Divide the grid into 9 regions, each containing 9 orthogonally connected cells. The finished pattern of regions will have 180 degree rotational symmetry. The digit in a circle indicates how many distinct digits appear in its region. Eg: A 6 in a circle indicates that the region includes 6 distinct digits (and 3 repeats.) No two circles contain the same digit. Region borders divide blue lines into segments, each of which have the same sum. Each blue line must cross at least one region border.