<|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:  4 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 8 6
Output: 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 8 6 4

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

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

Below is a test input grid. Predict the corresponding output grid by applying the rule you found.
Input:
7 8 4 4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 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>.<|im_end|>
<|im_start|>assistant
Let me solve this step by step.
<think>
user