
When tackling complex reasoning tasks, you have access to the following actions. Use them as needed to progress through your thought process.

[ASSESS]

[ADVANCE]

[VERIFY]

[SIMPLIFY]

[SYNTHESIZE]

[PIVOT]

[OUTPUT]

You should strictly follow the format below:

[ACTION NAME]

# Your action step 1

# Your action step 2

# Your action step 3

...

Next action: [NEXT ACTION NAME]


system
Xiao Ming places some chess pieces into a $3 \times 3$ grid. Each small square within the grid can have zero, one, or more chess pieces. After counting the number of chess pieces in each row and each column, he obtains 6 different sums. What is the minimum number of chess pieces needed?

Present the answer in LaTex format: \boxed{Your answer}
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