+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
|                   |                   |                       |
+   +   +---+   +   +   +   +   +   +   +   +   +   +   +   +   +
|       |                     s                         |       |
+   +   +   +   +   +   +   +   +   +   +   +   +   +---+   +---+
|                                                               |
+   +   +   +   +   +   +   +   +   +---+   +   +   +   +   +   +
|                       |           |                           |
+   +   +   +   +   +   +---+   +   +   +   +   +   +   +---+   +
|                                                           |   |
+---+   +   +   +---+   +   +   +   +   +   +   +   +   +   +   +
|         b         |                                           |
+   +   +   +   +   +   +   +   +   +   +   +   +   +   +   +   +
|       |                                       |               |
+   +---+   +   +   +   +   +---+---+   +   +   +---+   +   +   +
|                           |   |   |                           |
+   +   +   +   +   +   +   +---+---+   +   +   +   +   +   +   +
|                           |   |   |             Y             |
+   +   +   +   +   +   +   +---+---+   +   +   +   +   +   +   +
|               |                                               |
+   +   +   +   +---+   +---+   +   +   +   +   +   +   +   +---+
|                       |         * |                           |
+---+   +   +   +   +   +   +   +---+   +   +   +   +---+   +   +
|                                             g     |           |
+   +   +   +   +   +   +   +---+   +   +   +   +   +   +   +   +
|         r                     |                               |
+   +---+   +   +   +   +   +   +   +   +   +   +   +   +   +   +
|       |                           |                           |
+   +   +   +   +   +   +   +   +   +---+   +   +   +   +---+   +
|               |                                           |   |
+   +   +   +---+   +   +   +   +   +   +   +   +   +   +   +   +
|                   |                           |               |
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+