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 X

Distractor grid 1:

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

Instruction: Describe the target grid.
Generate the referring expression starting with the tag "Expression: " for the given target grid. Omit any other text.
Expression: The grid with a horizontal line of empty cells in the middle. 

assistant
Expression: The target grid has a unique pattern of five rows and five columns, where all cells are filled except for one empty cell in the middle row and column, forming an X-shaped void. This void is surrounded by nine Xs in each direction. The distractor grids have different patterns with some cells being empty and others filled. Distractor 1 has alternating rows of five Xs and four empty cells, while distractor 2 has all cells filled except for one row
assistant