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:  7 3 8 6 8 0 0 0 0 0 0 5 5 9 4 1 7 1 7 4 6
Output: 6 8 0 0 0 0 0 0 5 5 9 4 1 7 1 7 4 6 7 3 8

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

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

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