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 X
▢ X X X X

Distractor grid 1:

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

Distractor grid 2:

X X ▢ X X
X X ▢ X X
X 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 consists of five rows, each containing a single column of empty cells on the left, followed by four columns of filled cells, creating a vertical line of empty cells on the left side.
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Expression: The grid where each row has one empty cell and the empty cell shifts one cell to the right in each subsequent row.<|im_end|><|im_end|>

The referring expression "The grid where each row has one empty cell and the empty cell shifts one cell to the right in each subsequent row" accurately describes the target grid by identifying its unique pattern where there is one empty cell (marked as "▢") in each row, and this empty cell moves one cell to the right in each successive
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