The mentalfloss.com Brain Game enters Think Thursday. Everyone should be able to solve today's challenge, provided you take a few moments to work it out. I've provided an example as well to help you along. Good luck!

For any positive whole number, if you count the number
of (English) letters used when spelling out that number,
and then use that value as the next number in the sequence
(and so on), you'll always end up stuck on number?

EXAMPLE: 27 is "twenty seven," which has 11 letters...
11 is "eleven" which has 6 letters...
6 is "six" which has 3 letters...

FOUR.

Once you reach the number four, the pattern loops, since it's the only number that has a value equal to the number of letters used to spell it. It may take a few steps, but it doesn't matter which positive number you start with, you'll end up at 4:

2 (two) = 3 (three) = 5 (five) = 4.

55 (fifty five) = 9 (nine) = 4.

899 (eight hundred ninety nine) = 20 (twenty) = 6 (six) = 3 (three) = 5 (five) = 4.

1,427,963 (one million four hundred twenty seven thousand nine hundred sixty three) = 61 (sixty one) = 8 (eight) = 5 (five) = 4.

Thanks for playing. Tomorrow, it's Free-for-all Friday!