This BrainBashers safe has a rather unusual control panel.
In order to open the safe, you have to press every single square once only, in the correct sequence, ending on the square marked E.
Each square indicates which square to press next, for example, 2U means move up 2 squares and 3R means move right 3 squares.
Can you determine which square you must start with?
Note: this puzzle isn't interactive, and the safe buttons can't be clicked.
| 3R | 4R | 2R | 2D | 2R | 4D | 2D |
| 2R | 1U | 1U | 3D | 2D | 1R | 2L |
| 3D | 1D | 3R | 1R | 2L | 4L | 1D |
| 1U | 4R | 2L | 3D | 2D | 2L | 4L |
| 4U | 1L | 2D | E | 2R | 1D | 4L |
| 1R | 1D | 1R | 4U | 2R | 3L | 1D |
| 5U | 5U | 2L | 2R | 2U | 5U | 2L |