Problem:
Score : 300 points

Problem Statement

You are playing the following game with Joisino.

Initially, you have a blank sheet of paper.

Joisino announces a number. If that number is written on the sheet, erase the number from the sheet; if not, write the number on the sheet. This process is repeated N times.

Then, you are asked a question: How many numbers are written on the sheet now?

The numbers announced by Joisino are given as A_1, ... ,A_N in the order she announces them. How many numbers will be written on the sheet at the end of the game?

Constraints

1≤N≤100000

1≤A_i≤1000000000(=10^9)

All input values are integers.

Input

Input is given from Standard Input in the following format:

N
A_1
:
A_N

Output

Print how many numbers will be written on the sheet at the end of the game.

Sample Input 1

3
6
2
6

Sample Output 1

1

The game proceeds as follows:

6 is not written on the sheet, so write 6.

2 is not written on the sheet, so write 2.

6 is written on the sheet, so erase 6.

Thus, the sheet contains only 2 in the end. The answer is 1.

Sample Input 2

4
2
5
5
2

Sample Output 2

0

It is possible that no number is written on the sheet in the end.

Sample Input 3

6
12
22
16
22
18
12

Sample Output 3

2

Solution in Haskell (GHC 7.10.3) (judge verdict: Time Limit Exceeded)

import Control.Monad
import Control.Applicative
import Data.List


main :: IO()
main = do
  n <- readLn :: IO Int
  lst <- replicateM n readLn :: IO [Int]
  let l = (foldl (\x -> \y -> x + ((length y) `mod` 2)) 0  . splitBySame) lst
  print  l



splitBySame ::  (Ord a) => [a] -> [[a]]
splitBySame [] = []
splitBySame list = let (x:xs) = sort list; (lst, rest) = split x [] xs in lst : splitBySame rest
    where
      split :: (Ord a) => a -> [a]-> [a] -> ([a], [a])
      split n acc [] = (n:acc, [])
      split n acc (x:xs)
                  | n == x = split n (x:acc) xs
                  | n /= x = (n:acc, x:xs)