
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 9x9 checkerboard is filled with the whole numbers from 1 through 81, following the same pattern as previously described—across each row from left to right, starting a new row right beneath the previous one. What is the sum of the numbers in the four corners of this checkerboard?
A) 150  
B) 160  
C) 164  
D) 170  
E) 180

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