Difficulty:

The look-and-say sequence is the sequence of numbers generated by describing each number to produce the next. The first few numbers are

`1`

,`11`

,`21`

,`1211`

, and`111221`

. The next number in the sequence is`312211`

, because the last one has "Three 1s, two 2s, and one 1". Given`n`

, produce the n-th number in the sequence. The output will not be longer than 20,000 characters.

lookAndSay(7);

"13112221"

- Hint #1