The aim is to color the whole grid in to black and white squares. At the top of each column, and at the side of each row, you will notice a set of one or more numbers. These numbers tell you the runs of black squares in that row/column. So, if you see '10 1', that tells you that there will be a run of exactly 10 black squares, followed by one or more white square, followed by a single black square. There may be more white squares before/after this sequence.