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 4 7 9 6 4 7 4 9 3 2 0 0 0 0 0 0 0 0 0 0 0 0 7 5
Output: 9 6 4 7 4 9 3 2 0 0 0 0 0 0 0 0 0 0 0 0 7 5 4 4 7

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

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

Below is a test input grid. Predict the corresponding output grid by applying the rule you found.
Input:
4 6 9 8 7 5 9 7 2 9 0 0 0 0 0 0 0 0 0 0 0 0 7 8 4
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