import qualified Control.Monad as M
import qualified Data.Char as C

main :: IO ()
main = do
  t <- read <$> getLine
  M.forM_ [1..t] $ \i -> do
    ss <- map C.digitToInt <$> getLine
    print $ proc ss

proc :: [Int] -> Int
proc ss = head . last . take (length ss) $ iterate sub ss

sub :: [Int] -> [Int]
sub [] = []
sub (_:[]) = []
sub (a:b:xs) = result : sub (b:xs)
  where result | a + b < 10 = a + b
               | otherwise  = ((a + b) `div` 10) + ((a + b) `mod` 10)