3    dimension

1    number of levels

-1.0 -1.0 -1.0   x_low
 1.0  0.0  1.0   x_high
 80  40  80   num_cells
   1    1    1   num_ghost_cells

4    number of grids

-1.0 -1.0 -1.0   x_low
 0.0  0.0  0.0   x_high

-1.0 -1.0  0.0   x_low
 0.0  0.0  1.0   x_high

 0.0 -1.0 -1.0   x_low
 1.0  0.0  0.0   x_high

 0.0 -1.0  0.0   x_low
 1.0  0.0  1.0   x_high
