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 ▢

Distractor grid 1:

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

Distractor grid 2:

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 single X in the top left corner, followed by an X in the third column of the first row. The second row has an X in the second column only. The third row has Xs in the first, third, and fifth columns. The fourth and fifth rows are identical, with an X in the third and fourth columns.
assistant
Expression: X ▢ X ▢ ▢
assistant