import Control.Applicative
import Control.Monad

sumPair = do
  x <- read <$> getLine
  y <- read <$> getLine
  if x + y < 10^79
    then putStrLn $ show $ x + y
    else putStrLn "overflow"

main = do
  n <- (read :: String -> Int) <$> getLine
  replicateM n sumPair