
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

Along a straight alley at equal intervals, there are 400 lampposts, numbered sequentially from 1 to 400. At the same time, Alla and Boris started walking towards each other from opposite ends of the alley with different constant speeds (Alla started from the first lamppost and Boris from the four-hundredth). When Alla reached the 55th lamppost, Boris was at the 321st lamppost. At which lamppost will they meet? If the meeting point is between two lampposts, indicate the smaller number of the two in your answer.

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