Paint some cells black to create walls. The numbersoutside the grid indicate the lengths of blackenedcell blocks in the corresponding directions, in order; as in a Paint By Number puzzle. If there is more than one blackened block in a row or column, theremust be at least one white cell between the blocks. After all black cells are determined, a snake should travel through all the unoccupied cells,moving horizontally or vertically without touchingitself, even diagonally. The head and the tail of the snake are given in circle.