
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
Given that the encryption rule is $a\rightarrow a-2b$ and $b\rightarrow 2a+b$, and the ciphertext is $1, 7$, calculate the decrypted plaintext.

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