An evil king locked a wizard in a dungeon with nothing but a chair and a shovel. There is a window in the room, but the wizard can't reach it using the chair. The dungeon is surrounded by a cement parking lot that stretches 100 feet in every direction.
The wizard uses the shovel to dig a 50 feet long tunnel and still manages to escape.
How?
THe first solution: a practical one:
The wizard digs a 50 ft tunnel at 45 degrees downwards and piles up the soil he digs out below the window. The pile of soil allows him to reach the window and escape.
Why 45 degrees downwards? Any steeper and the wizard might find he cannot get out of the tunnel he has dug.
The second solution: a migical one
The wizard is a wizard so just uses magic to 'magic' his way out