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

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

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

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