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:
Yellow Black Pink Black
Black Brown Black Black
Black Black Purple Black
Black Black Black Black

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


Example 2
Input:
Black Blue Black Green
Red Black Black Black
Black Blue Black Black
Black Black Black Black

Output:
Black Green Black Green
Black Black Black Black
Green Black Black Green
Black Black Black Black


Example 3
Input:
Black Black Black Yellow
Black Black Black Black
Black Black Black Black
Green Black Black Black

Output:
Black Yellow Black Yellow
Black Black Black Black
Yellow Black Black Yellow
Black Black Black Black


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

```
Gray Gray Black Black
Black Black Gray Gray
Gray Gray Black Black
Black Black Gray Gray
```
assistant