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 filled cells in the middle row, and two full rows at the bottom except for the fourth column.
assistant
Expression: The target grid has a 3x3 square of filled cells in the center, with two filled cells in the bottom row and one filled cell in the top row.
assistant