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:  3 8 1 4 2 0 0 0 0 0 0 0 0 0 0 0 0 3 2 9 9 8
Output: 4 2 0 0 0 0 0 0 0 0 0 0 0 0 3 2 9 9 8 3 8 1

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

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

Below is a test input grid. Predict the corresponding output grid by applying the rule you found.
Input:
7 8 8 8 2 3 0 0 0 0 0 0 2 3 5 3 8 7 5 8 5 1
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