<|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 8 0 0 0 2 0 5 0 1 0 7 4 9 0 8 6 0 0
Output: 0 0 0 0 0 0 0 0 0 1 8 2 5 1 7 4 9 8 6

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

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

Below is a test input grid. Predict the corresponding output grid by applying the rule you found.
Input:
6 0 5 8 8 4 4 2 3 2 0 7 0 0 0 1 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