<|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:  5 2 9 3 7 8 2 6 0 0 0 0 0 0 0 0 0 0 0 0 0 0 5 3 7 1 1 8 8
Output: 2 9 3 7 8 2 6 0 0 0 0 0 0 0 0 0 0 0 0 0 0 5 3 7 1 1 8 8 5

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

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

Below is a test input grid. Predict the corresponding output grid by applying the rule you found.
Input:
1 6 4 2 5 1 8 0 0 0 0 0 0 0 0 0 4 8 5 2 7 9 2 5 7 9 4 1 5
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