{year=>2015}

--- Day 10: Elves Look, Elves Say ---

Today, the Elves are playing a game called look-and-say. They take turns making sequences by reading aloud the previous sequence and using that reading as the next sequence. For example, `211` is read as "one two, two ones", which becomes `1221` (`1` `2`, `2` `1`s).

Look-and-say sequences are generated iteratively, using the previous value as input for the next step. For each step, take the previous value, and replace each run of digits (like `111`) with the number of digits (`3`) followed by the digit itself (`1`).

For example:

• `1` becomes `11` (`1` copy of digit `1`).
• `11` becomes `21` (`2` copies of digit `1`).
• `21` becomes `1211` (one `2` followed by one `1`).
• `1211` becomes `111221` (one `1`, one `2`, and two `1`s).
• `111221` becomes `312211` (three `1`s, two `2`s, and one `1`).

Starting with the digits in your puzzle input, apply this process 40 times. What is the length of the result?

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