{-# OPTIONS_GHC -Wall -Werror #-}

import Control.Monad

main :: IO ()
main = do
  n <- readLn :: IO Int
  replicateM_ n $ do
    [a, b] <- replicateM 2 readLn :: IO [Integer]
    let answer = show $ a + b
        digits = length answer
    if digits >= 80 then putStrLn "overflow"
                    else putStrLn answer