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 grid with two X's in the middle row and two X's in the fourth row, forming a square shape in the center.
assistant
Expression: The grid contains two filled cells in the last row, one in the first column and one in the fourth column, while the second row has a filled cell in the third and fifth columns, and the third and fourth rows each have two filled cells in the second and third columns.
assistant