
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
Two small rulers form a set square, where the small ruler can slide along the large ruler. Each unit on the large ruler is marked with natural numbers. The first small ruler divides 11 units on the large ruler into 10, and the second small ruler divides 9 units on the large ruler into 10. The starting points of both small rulers are 0, marked from 1 to 10 respectively. Now measure the distance between points \(A\) and \(B\), with point \(A\) at 0 units on the large ruler, and point \(B\) between 18 and 19 units on the large ruler. When the 0 unit of the first small ruler is placed at point \(B\), its 3rd unit coincides with a certain unit on the large ruler. If the 0 unit of the second small ruler is placed at point \(B\), then which unit of the second small ruler coincides with a certain unit on the large ruler?

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