<|im_start|>system
You are a helpful assistant. You first think about the reasoning process in the mind and then provides the user with the answer.<|im_end|>
<|im_start|>user
Find the common rule that maps an input grid to an output grid, given the examples below.

Example 1:
Input:  1 2 0 0 7 0 9 9 0 0 4 0 6 8 9 0 0 8 0 0 0 1 8 0 6 8
Output: 0 1 2 0 0 7 0 9 9 0 0 4 0 6 8 9 0 0 8 0 0 0 1 8 6 8

Example 2:
Input:  9 8 3 1 8 2 0 6 9 0 0 7 7 5 4 3 2 0 4 9 3 0 5 0 4 3
Output: 0 9 8 3 1 8 2 0 6 9 0 0 7 7 5 4 3 2 0 4 9 3 0 5 4 3

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

Below is a test input grid. Predict the corresponding output grid by applying the rule you found.
Input:
6 6 1 0 9 4 3 3 1 0 0 1 0 5 9 1 0 0 0 0 5 0 6 8 0 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>.<|im_end|>
<|im_start|>assistant
Let me solve this step by step.
<think>
user