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

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

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

Below is a test input grid. Predict the corresponding output grid by applying the rule you found.
Input:
3 5 9 9 0 0 0 0 8 5 2 3 4 8 4 3 2 9 9 8 9 7 2 3 8
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