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:  6 2 8 9 0 0 0 0 9 6 7 6 2 4 7 3 4
Output: 2 8 9 0 0 0 0 9 6 7 6 2 4 7 3 4 6

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

Example 3:
Input:  3 1 7 0 0 0 0 0 0 0 0 8 5 8 8 4 3
Output: 1 7 0 0 0 0 0 0 0 0 8 5 8 8 4 3 3

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