import Data.List (intercalate)

data Interval = Interval Int Int

instance Show Interval where
    show (Interval start end)
        | start == end = show start
        | otherwise    = show start ++ "-" ++ show end

singletonInterval :: Int -> Interval
singletonInterval x = Interval x x

extendIntervals :: Int -> [Interval] -> [Interval]
extendIntervals val [] = [singletonInterval val]
extendIntervals val intervals
    | firstIntervalStart - val == 1 = Interval val firstIntervalEnd : otherIntervals
    | otherwise                     = singletonInterval val : intervals
    where Interval firstIntervalStart firstIntervalEnd = head intervals
          otherIntervals                               = tail intervals

convertToIntervals :: [Int] -> [Interval]
convertToIntervals = foldr extendIntervals []

main = do
    input <- getContents
    putStrLn $ intercalate "," . map show . convertToIntervals . map read . words $ input