Problem 17

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.

If all the numbers from $1$ to $1000$ (one thousand) inclusive were written out in words, how many letters would be used?

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.

整数英文表达的字母计数

把 $1$ 到 $5$ 写成英文单词分别是：one、two、three、four、five。这些单词一共用了 $3 + 3 + 5 + 4 + 4 = 19$ 个字母。

如果把 $1$ 到 $1000$ 都写成英文单词，一共要用多少个字母？

注意： 不计入空格和连字符：例如， $342$ （three hundred and forty-two）包含 $23$ 个字母，而 $115$ （one hundred and fifteen）包含 $20$ 个字母。单词“and”的使用方式遵循英式英语的规则。