{-# LANGUAGE BangPatterns #-}
import Control.Monad
import Control.Applicative

addFixed :: [Int] -> [Int] -> [Int]
addFixed = iter 0 where
    iter s [] [] = let (p,q) = s `divMod` 10 in [q,p]
    iter s xs [] = iter s xs [0]
    iter s [] ys = iter s [0] ys
    iter !s (x:xs) (y:ys) = let
        (surp,n) = (x+y+s) `divMod` 10
        in n: iter surp  xs ys

main = do
    n <- readLn
    replicateM_ n $ do
        x <- reverse . map (read . return) <$> getLine
        y <- reverse . map (read . return) <$> getLine
        let s = concatMap show . dropWhile (== 0) . reverse $ addFixed x y
        putStrLn $ if length s > 80
                        then "overflow"
                        else s