<|im_start|>system
You are a helpful assistant. You first think about the reasoning process in the mind and then provides the user with the answer.<|im_end|>
<|im_start|>user
Find the common rule that maps an input grid to an output grid, given the examples below.

Example 1:
Input:  9 5 2 5 3 0 0 0 0 0 0 0 0 0 0 0 0 0 5 3 9 1
Output: 5 3 9 1 9 5 2 5 3 0 0 0 0 0 0 0 0 0 0 0 0 0

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

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

Below is a test input grid. Predict the corresponding output grid by applying the rule you found.
Input:
9 7 4 4 4 5 8 3 7 0 0 0 0 0 0 0 0 0 0 0 5 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>.<|im_end|>
<|im_start|>assistant
Let me solve this step by step.
<think>
user