
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 the store "Third is not superfluous," there is a promotion: if a customer presents three items at the checkout, the cheapest one of them is free. Ivan wants to buy 11 items costing $100, 200, 300, ..., 1100 rubles. What is the minimum amount of money he can spend to buy these items?

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