
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
The teacher wrote a four-digit number on a piece of paper for Xiaowei to guess. They had four rounds of questions and answers.
Xiaowei: "Is it 8765?"
Teacher: "You guessed two digits correctly, but both are in the wrong positions."
Xiaowei: "Is it 1023?"
Teacher: "You guessed two digits correctly, but both are in the wrong positions."
Xiaowei: "Is it 8642?"
Teacher: "You guessed two digits correctly, and both are in the correct positions."
Xiaowei: "Is it 5430?"
Teacher: "None of the digits are correct."
What is this four-digit number $\qquad$?

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