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:  8 2 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 7
Output: 7 8 2 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

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

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

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