import Control.Monad
import Control.Applicative

parse :: IO ()
parse = do
    [a, b] <- replicateM 2 $ (read :: String -> Integer) <$> getLine
    let s = show $ a + b
    if (length s) > 80
    then putStrLn "overflow"
    else putStrLn s

main :: IO ()
main = do
    n <- read <$> getLine
    replicateM_ n parse