
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
For any real number sequence $A=\{a_1, a_2, a_3, \ldots\}$, define $D(A)$ as the sequence $\{a_2-a_1, a_3-a_2, \ldots\}$, where its $n$-th term is $a_{n+1}-a_n$. Suppose all terms of the sequence $D(DA)$ are equal to 1, and $a_{19}=a_{92}=0$, then $a_1= \boxed{\text{\_\_\_\_\_\_}}$.

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