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

Distractor grid 1:

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

Distractor grid 2:

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 has a solid border of filled cells on all four sides, with a filled 3x3 square in the top-left corner and a filled 3x3 square in the bottom-right corner.
assistant
Expression: The grid that has a row of five filled cells at the top, and a column of three filled cells in the middle.
assistant