maze solving algorithms (pledge algorithm)
If you use wall following with the right hand, you should place your hand on the right wall.

For the pledge algorithm your source says


  It's a guaranteed way to reach an exit on the outer edge of any 2D Maze from any point in the middle, however it's not able to do the reverse, i.e. find a solution within the Maze.


There is no guarantee that the exit reached is the one labeled "Exit" instead of the one labeled "Start".