{-# OPTIONS_GHC -O2 #-}
{-# LANGUAGE BangPatterns          #-}
{-# LANGUAGE CPP                   #-}
{-# LANGUAGE LambdaCase            #-}
{-# LANGUAGE MagicHash             #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE MultiWayIf            #-}
{-# LANGUAGE OverloadedStrings     #-}
{-# LANGUAGE TupleSections         #-}
{-# LANGUAGE TypeFamilies          #-}
{-# LANGUAGE ViewPatterns          #-}

import           Control.Applicative
import           Control.Exception
import           Control.Monad
import           Control.Monad.Primitive
import           Control.Monad.ST
import           Control.Monad.State.Strict
import           Data.Bool
import qualified Data.ByteString             as B
import qualified Data.ByteString.Char8       as C
import qualified Data.ByteString.Unsafe      as B
import           Data.Char
import qualified Data.Foldable               as F
import           Data.Function
import qualified Data.IntMap.Strict          as IM
import qualified Data.IntSet                 as IS
import qualified Data.List                   as L
import qualified Data.Map.Strict             as M
import           Data.Monoid
import           Data.Ord
import           Data.Primitive.MutVar
import qualified Data.Set                    as S
import           Data.Tuple
import qualified Data.Vector                 as V
import qualified Data.Vector.Mutable         as VM
import qualified Data.Vector.Generic         as G
import qualified Data.Vector.Generic.Mutable as GM
import qualified Data.Vector.Unboxed         as U
import qualified Data.Vector.Unboxed.Mutable as UM
import           Debug.Trace
import           Foreign                     hiding (void)
import           GHC.Exts
import           Unsafe.Coerce

main :: IO ()
main = do
    !n <- readLn :: IO Int
    abcs <- U.unfoldrN (2*(n-1)+n) (C.readInt.C.dropWhile isSpace) <$> C.getContents
    let (ab, cs) = U.splitAt (2*(n-1)) abcs
    let (m, ds) = solve n (U.unfoldrN (n-1) parse ab) cs
    print m
    putStr.unwords.map show$U.toList ds

parse :: U.Vector Int -> Maybe ((Int, Int), U.Vector Int)
parse vec = Just ((a, b), U.drop 2 vec)
  where
    !a = U.unsafeIndex vec 0 - 1
    !b = U.unsafeIndex vec 1 - 1

nothing :: Int
nothing = -1

solve :: Int -> U.Vector (Int, Int) -> U.Vector Int -> (Int, U.Vector Int)
solve n edges (radixSort64 -> cs) = (score, res)
  where
    !score = U.sum $ U.map (\(a, b) -> U.unsafeIndex res a `min` U.unsafeIndex res b)edges
    !res = U.unsafeAccumulate (flip const) (U.replicate n nothing)
        . U.imap (\i j -> (j, U.unsafeIndex cs i))
        $ indices
    indices = U.create $ do
        deg <- UM.replicate n (0 :: Int)
        que <- newQueueM
        gr <- VM.replicate n []
        U.forM_ edges $ \(a, b) -> do
            UM.unsafeModify deg (+1) a
            UM.unsafeModify deg (+1) b
            VM.unsafeModify gr (a:) b
            VM.unsafeModify gr (b:) a
        rep n $ \i -> do
            d <- UM.unsafeRead deg i
            when (d == 1) $ do
                enqueueM i que
        fix $ \loop -> do
            dequeueM que >>= \case
                Nothing -> return ()
                Just x -> do
                    UM.unsafeWrite deg x 0
                    nexts <- VM.unsafeRead gr x
                    F.forM_ nexts $ \nx -> do
                        deg' <- UM.unsafeRead deg nx
                        when (deg' == 2) $ do
                            enqueueM nx que
                        UM.unsafeModify deg (subtract 1) nx
                    loop
        return . UM.take n $ queueData que



-------------------------------------------------------------------------------
rep :: Monad m => Int -> (Int -> m ()) -> m ()
rep n = U.forM_ (U.generate n id)
{-# INLINE rep #-}

data VecQueue m a = VecQueue
    { queueInfo :: !(UM.MVector m Int)
    , queueData :: !(UM.MVector m a)
    }

newQueueM :: (PrimMonad m, UM.Unbox a) => m (VecQueue (PrimState m) a)
newQueueM = VecQueue <$> UM.replicate 2 0 <*> UM.unsafeNew (1024 * 1024)

dequeueM :: (PrimMonad m, UM.Unbox a) => VecQueue (PrimState m) a -> m (Maybe a)
dequeueM (VecQueue info q) = do
    h <- UM.unsafeRead info 0
    t <- UM.unsafeRead info 1
    if h < t
    then do
        UM.unsafeWrite info 0 (h + 1)
        pure <$> UM.unsafeRead q h
    else return Nothing
{-# INLINE dequeueM #-}

enqueueM :: (PrimMonad m, UM.Unbox a) => a -> VecQueue (PrimState m) a -> m ()
enqueueM x (VecQueue info q) = do
    t <- UM.unsafeRead info 1
    UM.unsafeWrite q t x
    UM.unsafeWrite info 1 (t + 1)
{-# INLINE enqueueM #-}

radixSort64 :: U.Vector Int -> U.Vector Int
radixSort64 v = F.foldl' step v [0, 16, 32, 48]
  where
    mask k x = fromIntegral $ unsafeShiftR x k .&. 0xffff
    step v k = U.create $ do
        pref <- U.unsafeThaw
            . U.prescanl' (+) 0
            . U.unsafeAccumulate (+) (U.replicate 0x10000 0)
            $ U.map (flip (,) 1 . mask k) v
        res <- UM.unsafeNew $ U.length v
        U.forM_ v $ \x -> do
            let !masked = mask k x
            i <- UM.unsafeRead pref masked
            UM.unsafeWrite pref masked $ i + 1
            UM.unsafeWrite res i x
        return res
{-# INLINE radixSort64 #-}

type Parser a = C.ByteString -> Maybe (a, C.ByteString)

parseInt :: Parser Int
parseInt = C.readInt . C.dropWhile isSpace

parseInt2 :: Parser (Int, Int)
parseInt2 = runStateT $
    (,) <$> StateT (C.readInt . C.dropWhile isSpace)
        <*> StateT (C.readInt . B.unsafeTail)

parseInt3 :: Parser (Int, Int, Int)
parseInt3 = runStateT $
    (,,) <$> StateT (C.readInt . C.dropWhile isSpace)
        <*> StateT (C.readInt . B.unsafeTail)
        <*> StateT (C.readInt . B.unsafeTail)

parseInt4 :: Parser (Int, Int, Int, Int)
parseInt4 = runStateT $
    (,,,) <$> StateT (C.readInt . C.dropWhile isSpace)
        <*> StateT (C.readInt . B.unsafeTail)
        <*> StateT (C.readInt . B.unsafeTail)
        <*> StateT (C.readInt . B.unsafeTail)