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
▢ ▢ ▢ ▢ ▢

Distractor grid 1:

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

Distractor grid 2:

▢ ▢ ▢ ▢ ▢
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 filled cells on the fourth row from the top.
assistant
Expression: The target grid has a unique X in the upper-left corner and another in the lower-right corner, surrounded by 14 empty cells. It is distinct from the distractors which have either four or five adjacent Xs in a row. Additionally, the distractor grids contain more than one contiguous row or column of filled cells. The target grid's organization of filled and empty cells creates a distinct pattern that sets it apart from the others.

Target
assistant