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".
You are also given a referring expression that describes one of the given grids.
Your task is to select the grid that matches the given referring expression.
Generate only the number (in text) of the grid that matches the given expression by selecting first, second, or third.

First:

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

Second:

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

Third:

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

Expression: The target grid has a rectangular shape with five rows and five columns. It has a total of ten filled cells, with five cells in each row and column. The filled cells are marked with "X" and are located in the top-left, top-right, bottom-left, and bottom-right corners of the grid. The remaining cells are empty and marked with "▢".
Question: Which grid does the expression refer to?
Start with the tag "Answer: ", followed by your selection. Omit any other text.

Answer: First
assistant
Answer: First
assistant