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: The target grid has a vertical line of empty cells on the rightmost column.
assistant
Expression: The target grid has four rows and five columns, where all cells in the first row are filled with Xs, while the remaining rows have alternating patterns of filled and empty cells. In particular, it does not resemble the distractor grids that have either a single row or column filled completely with Xs.
assistant