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

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

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

Below is a test input grid. Predict the corresponding output grid by applying the rule you found.
Input:
9 2 2 0 0 0 0 0 0 4 2 3 6 7 4 3 4 4 5 9
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