Snake

Snake (Tunnel) is a logic puzzle. Blacken some cells of the grid to make the black cells form a “snake” according to the rules.

Rules: Colour the grey cells of the grid black or white. The black cells form a “snake” that is exactly one cell wide, begins or ends in the two marked cells, and does not touch itself anywhere, not even diagonally.
A number at the left and top edges of the grid indicates how many cells in the corresponding row or column are to be blackened.