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 Ruby (2.7.1) (judge verdict: Accepted)

class Problem
  attr_accessor :a, :b, :n, :m, :h, :w

  def initialize
    @n = gets.to_s.to_i
    @a = Array.new(n){ gets.to_s.to_i }.sort
  end

  def solve
    ans = 0
    each do |n|
      ans += 1 if n.odd?
    end
    ans
  end

  def each
    cnt = 1
    n.times do |i|
      if i == n - 1 || a[i] != a[i+1]
        yield cnt
        cnt = 1
      else
        cnt += 1
      end
    end
  end

  def show(ans)
    puts ans
  end
end

Problem.new.instance_eval do
  show(solve)
end