module Main where

import Control.Applicative
import Numeric
import Data.Char


main :: IO ()
main = loop

loop :: IO()
loop = do
    {[n] <- getIntegers
    ; if n == 0 then return ()
      else do
      { print (sum (map digitToInt (show n)))
       ;loop
      }
    }


--
getIntegers :: IO[Integer]
getIntegers = map read. words <$> getLine

getInts :: IO [Int]
getInts = map read . words <$> getLine

putInts :: [Int] -> IO()
putInts = putStrLn . unwords . map show

getDoubles :: IO [Double]
getDoubles = map read . words  <$> getLine

putDoubles :: [Double] -> IO()
putDoubles = putStrLn . unwords . map showDouble

showDouble :: Double -> String
showDouble d = showFFloat Nothing d ""


