
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
In a regression model involving two variables, y and x, four different models were chosen. Their correlation coefficients R are as follows: ① The correlation coefficient R of Model 1 is 0.98; ② The correlation coefficient R of Model 2 is 0.80; ③ The correlation coefficient R of Model 3 is 0.50; ④ The correlation coefficient R of Model 4 is 0.25. Among them, the model with the best fitting effect is. (Fill in the serial number)

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