import Control.Applicative
import Control.Monad

sumPair = do
  x <- (read :: String -> Integer) <$> getLine
  y <- (read :: String -> Integer) <$> getLine
  if x+y < 10^79
    then putStrLn $ x+y
    else putStrLn "overflow"

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