Normal sudoku rules apply. Shade the grid using two colours, such that all instances of each colour are orthogonally connected, and no 2x2 area is completely one colour. Blue lines must have an equal sum N within each colour they pass through. If a blue line passes through a colour multiple times, each individual pass sums to N. (N can be different for different lines). All lines must cross colours at least once. Cells separated by an X contain digits summing to 10.