
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
To enhance students' mathematical literacy, the school offers three elective courses for 11th-grade students: "History of Mathematics", "Symmetry and Groups", and "Geometry on the Sphere". It is known that there are 600 students in the 11th grade, and each of them participates in only one elective course. To understand the students' learning situation in elective courses, a stratified sampling method is used to select 30 students for a discussion. According to statistics, the number of students participating in "History of Mathematics", "Symmetry and Groups", and "Geometry on the Sphere" forms an arithmetic sequence with a common difference of $-40$. The number of students that should be selected for the "History of Mathematics" course is ______.

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