Normal sudoku rules apply. For each line, digits on the line have an equal sum N within each 3x3 box it passes through. Eg r5c2 + r6c3 = r7c4 + r8c4 + r9c4 = r8c3 + r9c3
Normal sudoku rules apply. For each line, digits on the line have an equal sum N within each 3x3 box it passes through. Eg r5c2 + r6c3 = r7c4 + r8c4 + r9c4 = r8c3 + r9c3