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 ▢ ▢

Distractor grid 1:

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

Distractor grid 2:

X ▢ ▢ ▢ 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 features two filled cells in the top row, one in the first column and one in the fifth column, with a single filled cell in the second row located in the second and fourth columns. The third, fourth, and fifth rows each contain a vertical column of filled cells in the third column, creating a distinct vertical line of three filled cells.
assistant
Expression: The grid with three vertical X's in the middle column and two X's in the top and bottom rows, one in the first and one in the last column.||
assistant