import qualified Data.ByteString.Char8 as B
import           Data.Maybe
import           Control.Monad

readInt = fst . fromJust . B.readInteger
getInt = readInt <$> B.getLine
getIntN n = map readInt <$> replicateM (fromIntegral n) B.getLine

main :: IO ()
main = do
    t <- read <$> getLine
    ss <- replicateM (fromIntegral t) getLine
    print ss
    putStr $ unlines $ map show $ solve ss

solve :: [String] -> [Integer]
solve ss = map solveOne ss

solveOne :: String -> Integer
solveOne number | read number < 10 = read number
solveOne number = if ans >= 10 then solveOne $ show ans else ans
    where numbers = toNumbers number
          ns = map (\(a,b) -> a + b) $ zip (take ((length numbers)-1) numbers) (drop 1 numbers)
          ns2 = map sumAllNumber ns
          ans = toNumber ns2

toNumbers :: String -> [Integer]
toNumbers num = [ read [i] | i <- num ]

toNumber :: [Integer] -> Integer
toNumber nums = sum $ map (\(idx, num) -> num * 10 ^ (len-idx)) $ zip [1 ..] nums
    where len = length nums

sumAllNumber :: Integer -> Integer
sumAllNumber digits = if digits >= 10 then sum $ toNumbers $ show digits else digits

numberAt :: Integer -> Integer -> Integer
numberAt at source = (source `div` 10 ^ (at-1)) `mod` 10