A conversation between User and Assistant. The user asks a question, and the Assistant solves it. The assistant first thinks about the reasoning process in the mind and then provides the user with the answer.
User: Find the common rule that maps an input grid to an output grid, given the examples below.

Example 1:
Input:  4 6 3 9 8 2 7 9 8 7 7 0 1 7 8 4 3 2 3 6 2 5 6
Output: 6 2 5 6 4 6 3 9 8 2 7 9 8 7 7 0 1 7 8 4 3 2 3

Example 2:
Input:  0 2 6 9 5 6 6 8 8 2 3 9 3 3 3 4 7 8 8 7 0 0 0
Output: 7 0 0 0 0 2 6 9 5 6 6 8 8 2 3 9 3 3 3 4 7 8 8

Example 3:
Input:  7 6 3 3 5 5 2 5 6 1 2 1 6 7 8 9 2 3 8 5 5 7 2
Output: 5 5 7 2 7 6 3 3 5 5 2 5 6 1 2 1 6 7 8 9 2 3 8

Below is a test input grid. Predict the corresponding output grid by applying the rule you found.
Input:
6 0 0 0 1 8 8 4 1 1 4 8 5 7 6 9 9 7 5 8 2 4 9
Show your work in <think> </think> tags, and return the answer in <answer> </answer> tags with space between each number. For example <answer> 1 3 5 7 </answer>.
Assistant: Let me solve this step by step.
<think>
user