
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 Louis Vuitton store in Shanghai had a number of pairs of sunglasses which cost an average of \  $$ 900 $ per pair. LiAngelo Ball stole a pair which cost \$  $ 2000$ . Afterwards, the average cost of sunglasses in the store dropped to \ $$ 890$ per pair. How many pairs of sunglasses were in the store before LiAngelo Ball stole? 

*2018 CCA Math Bonanza Individual Round #3*

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