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 9 6 0 0 0 0 0 0 0 0 0 0 3 9 7 2 3 3 2 2 1 9 1
Output: 6 0 0 0 0 0 0 0 0 0 0 3 9 7 2 3 3 2 2 1 9 1 3 9

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

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

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