
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
Let $x$ be a natural number. If a sequence of natural numbers $x_{0}=1, x_{1}, x_{2}, \cdots, x_{l-1}, x_{l}=x$, satisfies $x_{i-1} < x_{i}$ and $x_{i-1} \mid x_{i}$ for $i=1,2, \cdots, l$, then $\left\{x_{0}, x_{1}, x_{2}, \cdots, x_{l}\right\}$ is called a factor chain of $x$, and $l$ is the length of this factor chain. $L(x)$ and $R(x)$ represent the length of the longest factor chain of $x$ and the number of the longest factor chains of $x$, respectively.

For $x = 5^{k} \times 31^{m} \times 1990^{n}$ (where $k, m, n$ are natural numbers), find $L(x)$ and $R(x)$.

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