
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 a square table consisting of $8 \times 8$ cells, there are natural numbers from 1 to 64 arranged in order. A number is selected from this table, and the row and column in which it is located are crossed out. From the remaining numbers, another number is selected and its row and column are also crossed out. This process is continued until all rows and columns have been crossed out. Find the sum of the eight selected numbers.

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