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44import Data.Char
english n
| n == 0 = "zero"
| n == 1 = "one"
| n == 2 = "two"
| n == 3 = "three"
| n == 4 = "four"
| n == 5 = "five"
| n == 6 = "six"
| n == 7 = "seven"
| n == 8 = "eight"
| n == 9 = "nine"
| n == 10 = "ten"
| n == 11 = "eleven"
| n == 12 = "twelve"
| n == 13 = "thirteen"
| n == 15 = "fifteen"
| n == 18 = "eighteen"
| n < 20 = (english ones) ++ "teen"
| n == 20 = "twenty"
| n == 30 = "thirty"
| n == 40 = "forty"
| n == 50 = "fifty"
| n == 60 = "sixty"
| n == 70 = "seventy"
| n == 80 = "eighty"
| n == 90 = "ninety"
| n < 100 = (english tens) ++ "-" ++ english ones
| n < 1000 && subHundreds == 0 = (english hundreds) ++ " hundred"
| n < 1000 = (english hundreds) ++ " hundred and " ++ english subHundreds
| n == 1000 = "one thousand"
| otherwise = undefined
where ones = n `mod` 10
tens = n `div` 10 * 10
hundreds = n `div` 100
subHundreds = n `mod` 100
main = print $ length $ filter isAlpha $ concat $ map english [1..1000]