
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
The number of solution-pairs $(x, y)$ in the positive integers of the equation $4x+7y=800$ is:
A) 26
B) 27
C) 28
D) 29
E) 30

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