chars = [str(i) for i in range(1, 10)]
linked_fields = ( [[start + offset for offset in range(9)] for start in [0, 18, 36, 54, 72, 90, 108, 129, 150] + [9, 27, 45, 63, 81, 99, 120, 141, 162] + [114, 135, 156, 171, 180, 189, 204, 225, 246] + [198, 219, 240, 261, 279, 297, 315, 333, 351] + [210, 231, 252, 270, 288, 306, 324, 342, 360]]
chars = [str(i) for i in range(1, 10)]
linked_fields = ( [[start + offset for offset in range(9)] for start in [0, 18, 36, 54, 72, 90, 108, 129, 150] + [9, 27, 45, 63, 81, 99, 120, 141, 162] + [114, 135, 156, 171, 180, 189, 204, 225, 246] + [198, 219, 240, 261, 279, 297, 315, 333, 351] + [210, 231, 252, 270, 288, 306, 324, 342, 360]]