
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
A student, Alex, participates in a special challenge where to earn the $n^{\text{th}}$ challenge point, the effort required increases in segments. For the first 10 challenge points, Alex does 1 activity each; for the next 10 points, 2 activities each; and for every successive group of 10 points, the number of activities increases by 1. Determine the smallest number of activities necessary for Alex to earn a total of 40 challenge points.

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