
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
Ella wants to write a number into each cell of a \(3 \times 3\) grid so that the sum of the numbers in any two cells that share an edge is the same. She has already written two numbers, as shown in the diagram. When Ella has completed the grid, what will be the sum of all the numbers in the grid?
A) 18
B) 20
C) 21
D) 22
E) 23

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