Number letter counts If the numbers 1 to 5 are written out in words: one, two, three, four, five, then there are 3 + 3 + 5 + 4 + 4 = 19 letters used in total.

Output how many letters would be used if all the numbers from 1 to 1000 (one thousand) inclusive were written out in words.

NOTE: Do not count spaces or hyphens. For example, 342 (three hundred and forty-two) contains 23 letters and 115 (one hundred and fifteen) contains 20 letters. The use of "and" when writing out numbers is in compliance with British usage.

You must actually calculate it - just printing the predetermined result is not allowed.

Output with any acceptable method.
Mathematica, 38 bytes

StringLength@StringJoin@IntegerName[Range[1000]]


@Doorknob has a leaner implementation:

Tr@StringLength@IntegerName@Range@1000


(* 20961 *)



Explanation

IntegerName[Range[10]]


(* {"one", "two", "three", "four", "five", "six", "seven", "eight", "nine", "ten"} *)

StringJoin@IntegerName[Range[10]]


(* "onetwothreefourfivesixseveneightnineten" *)

StringLength@StringJoin@IntegerName[Range[10]]


(* 39 *)