
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
Find the sum of the digits in the answer to the following expression:
$\underbrace{8888\cdots 88}_{80\text{ eights}} \times \underbrace{5555\cdots 55}_{80\text{ fives}} + \underbrace{1111\cdots 11}_{80\text{ ones}}$,
where strings of $80$ eights and $80$ fives are multiplied, then added to a string of $80$ ones.
A) 360
B) 400
C) 440
D) 480

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