
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
Let the set \( M = \{1, 2, \cdots, 2020\} \). The subset \( A \subseteq M \) is such that for any element \( x \) in \( A \), \( 4x \) is not in \( A \). What is the maximum number of elements in the set \( A \)?

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