You are given three grids, where each of them is 5 by 5 in size.
Grids have empty cells marked with "▢" and filled cells marked with "X".
Your task is to generate a referring expression that best describes the target grid while distinguishing it from the two other distractor grids.
The first grid is the target grid, and the following two grids are the distractors.

Target grid:

X ▢ X X X
X ▢ X X X
X ▢ X X X
X ▢ X X X
X ▢ X X X

Distractor grid 1:

▢ X X X X
▢ X X X X
▢ X X X X
▢ X X X X
▢ X X X X

Distractor grid 2:

X X ▢ X X
X X ▢ X X
X X ▢ X X
X X ▢ X X
X X ▢ X X

Instruction: Describe the target grid.
Generate the referring expression starting with the tag "Expression: " for the given target grid. Omit any other text.
Expression: A uniformly filled 5x5 grid with filled cells marked as "X" and empty cells as "▢", distinct from a completely filled grid and a grid with a diagonal line of empty cells.<|end|>
assistant
Expression: The grid with horizontal lines of filled and empty cells, where the filled cells are in the outermost columns and the empty cells are in the middle column.
assistant