{-# OPTIONS_GHC -O2 #-}
{-# LANGUAGE BangPatterns          #-}
{-# LANGUAGE CPP                   #-}
{-# LANGUAGE LambdaCase            #-}
{-# LANGUAGE MagicHash             #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE MultiWayIf            #-}
{-# LANGUAGE OverloadedStrings     #-}
{-# LANGUAGE RecordWildCards       #-}
{-# 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                 hiding (First(..))
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
    es <- U.map(\(x, y)->(x-1, y-1))
        . U.unfoldrN (n - 1) parseInt2 <$> C.getContents
    print $ solve n es

data Answer = First | Second deriving Show

solve :: Int -> U.Vector (Int, Int) -> Answer
solve n es
    | diameter gr `mod` 3 == 1 = Second
    | otherwise = First
  where
    gr = undirectedGraph (U.replicate n ()) es

type VertexId = Int
type EdgeId = Int
type Vertex = ()
type Edge = (Int, Int)

data Graph v e = Graph
    { adjacent :: V.Vector (U.Vector EdgeId)
    , vertices :: U.Vector v
    , edges :: U.Vector e
    }

undirectedGraph
    :: (U.Unbox v)
    => U.Vector v -> U.Vector (Int, Int) -> Graph v Edge
undirectedGraph vs es = runST $ do
    adj <- VM.replicate numV ([] :: [EdgeId])
    ues <- UM.unsafeNew numE
    flip U.imapM es $ \i (x, y) -> do
        let !ex = 2 * i
        let !ey = 2 * i + 1
        UM.unsafeWrite ues ex (x, y)
        UM.unsafeWrite ues ey (y, x)
        VM.unsafeModify adj (ex:) x
        VM.unsafeModify adj (ey:) y
    Graph
        <$> fmap (V.map (U.force . U.fromList)) (V.unsafeFreeze adj)
        <*> pure vs
        <*> U.unsafeFreeze ues
  where
    numV = U.length vs
    numE = 2 * U.length es

shortestPath :: (U.Unbox v) => Graph v Edge -> VertexId -> U.Vector Int
shortestPath Graph{..} root = U.create $ do
    dist <- UM.unsafeNew (U.length vertices)
    UM.unsafeWrite dist root 0
    U.forM_ (V.unsafeIndex adjacent root) $ \rootE ->
      flip fix rootE $ \dfs ei -> do
          let (p, v) = U.unsafeIndex edges ei
          UM.unsafeRead dist p >>= UM.unsafeWrite dist v . (+1)
          U.forM_ (V.unsafeIndex adjacent v) $ \i -> do
              let (_, nv) = U.unsafeIndex edges i
              when (nv /= p) $
                dfs i
    return dist

diameter :: (U.Unbox v) => Graph v Edge -> Int
diameter tree = U.maximum
    . shortestPath tree
    . U.maxIndex
    $ shortestPath tree 0

height :: (U.Unbox v) => Graph v Edge -> U.Vector Int
height tree = U.zipWith max fromS fromT
  where
    s = U.maxIndex $ shortestPath tree 0
    fromS = shortestPath tree s
    t = U.maxIndex fromS
    fromT = shortestPath tree t

-------------------------------------------------------------------------------
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)

Measured memory_bytes: 85372