import Data.Monoid
import Data.Text
import Data.Functor

toTuple::[a]->(a,a)
toTuple (a:b:_) = (a,b)

readInt::String->Int
readInt=read

main = 
	putStrLn
	=<<show
	<$>getSum
	<$>uncurry (<>)
	<$>toTuple
	<$>fmap ((Sum).readInt.unpack)
	<$>split (==' ')
	<$>pack 
	<$>getLine