
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
Arrange the positive odd numbers as shown in the pattern below. What is the 5th number from the left in the 21st row?

$$
1 \\
3 \quad 5 \quad 7 \\
9 \quad 11 \quad 13 \quad 15 \quad 17 \\
19 \quad 21 \quad 23 \quad 25 \quad 27 \quad 29 \quad 31 \\
\ldots \quad \quad \quad \ldots \quad \quad \quad \ldots
$$

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