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

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

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

Below is a test input grid. Predict the corresponding output grid by applying the rule you found.
Input:
6 2 6 9 6 8 3 4 9 5 0 0 0 0 0 0 0 0 0 0 0 0 2 4
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