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:
Green Yellow Yellow Blue
Green Yellow Green Blue
Blue Green Blue Blue
Blue Red Green Green

Output:
Blue
Black
Black
Black


Example 2
Input:
Blue Green Blue Blue
Yellow Red Yellow Blue
Green Blue Green Red
Red Green Red Blue

Output:
Blue
Black
Black
Black


Example 3
Input:
Blue Blue Red Red
Yellow Yellow Yellow Blue
Green Green Green Green
Red Blue Red Blue

Output:
Red
Black
Black
Black


Here is the input grid for the test example:
Input:
Red Red Green Green
Red Green Red Blue
Green Yellow Red Red
Yellow Blue Red Red


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:

```
Green
Black
Black
Black
```
assistant