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 ▢ ▢ ▢ ▢

Second:

▢ ▢ ▢ ▢ 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

Expression: The target grid has a single row of all X's at the bottom, with the remaining cells being a checkerboard pattern of X's and ▢'s.
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