import Control.Applicative
main = do
  _ <- (read::String->Integer) <$> getLine
  s<-getContents
  let v = cut2 . map (read::String->Integer) . lines $ s
  mapM_ (putStrLn . aux) v
  where
    cut2::[Integer] -> [[Integer]]
    cut2 [] = []
    cut2 xs = (take 2 xs):(cut2(drop 2 xs))

aux::[Integer]->String
aux [l,m] =  if (length . show $ s) > 80 then
               "overflow"
             else
               show s
  where s = l + m