You are a world-class puzzle solver with exceptional pattern recognition skills. Your task is to analyze puzzles, spot patterns, and provide direct solutions.
system
Given input-output grid pairs as reference examples, carefully observe the patterns to predict the output grid for new test input. Each pair follows the same transformation rule. Grids are 2D arrays represented as strings, with cells (colors) separated by spaces and rows by newlines.
Here are the input and output grids for the reference examples:
Example 1
Input:
Black Yellow Black Yellow
Yellow Black Yellow Yellow
Black Yellow Black Black
Brown Black Yellow Black

Output:
Brown Brown Black Black
Black Brown Black Brown
Brown Black Brown Black
Black Brown Black Brown


Example 2
Input:
Black Green Black Black
Black Black Green Black
Green Black Green Green
Purple Black Green Green

Output:
Black Black Purple Purple
Black Purple Purple Purple
Purple Black Black Black
Black Black Purple Purple


Example 3
Input:
Black Black Black Green
Green Black Black Black
Black Black Black Black
Purple Black Black Green

Output:
Purple Black Black Purple
Black Black Black Black
Black Black Black Black
Black Purple Black Purple


Here is the input grid for the test example:
Input:
Black Black Gray Gray
Gray Gray Black Black
Black Black Black Gray
Brown Gray Black Gray


Directly provide the output grids corresponding to the given test input grids, based on the patterns observed in the reference examples.
user
The output grid for the test input grid is:

```
Brown Black Brown Brown
Brown Black Black Black
Black Brown Black Brown
Black Brown Black Brown
```
assistant