{-# OPTIONS -Wall #-}
{-# OPTIONS -fno-full-laziness #-}
import Debug.Trace

foo :: String -> Int
foo s
  | trace "foo entered" False = undefined
  | trace ("foo got " ++ show (length s)) False = undefined
  | otherwise = length s

foos :: Int -> Int
foos n = sum $ map foo [show i | i <- [1..n]]

main :: IO ()
main = print (foos 100)