listToTupleTwo []       = []
listToTupleTwo (x:y:xs) = (x,y) : (listToTupleTwo xs)

digitNumber :: Integer -> Integer
digitNumber 0 = 0
digitNumber n = (digitNumber (n`div`10)) + 1

sumTuple :: (Integer,Integer) -> String
sumTuple a = if digitNumber(fst a) > 80 || digitNumber(snd a) > 80 || digitNumber(fst a + snd a) > 80
                then "overflow"
                else show(fst a + snd a)

main = do{
    n <- getLine;
    getContents>>=mapM_ putStrLn.map sumTuple.listToTupleTwo.map (read::String->Integer).lines;
}