
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 was solving a math problem: "Find the value of the algebraic expression $10x^9 + 9x^8 + 8x^7 + 7x^6 + 6x^5 + 5x^4 + 4x^3 + 3x^2 + 2x + 1$ when $x = -1$." Due to mistaking a "+" sign for a "-" sign in one of the terms, he incorrectly calculated the value of the expression as 7. How many "+" signs did Xiao Ming misread?

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