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 Fortran (gfortran v4.8.4) (judge verdict: Time Limit Exceeded)

program main
implicit none
integer :: i, j, k
integer :: n
integer , allocatable :: a(:), b(:)

read(*,*) n
allocate( a(n), b(n) )
b(1) = 0
do i = 1, n
   read(*,*) a(i)
   k = 1
   do j = 1, i
      if( a(i) == b(j) ) then
         k = 0
         b(j) = 0
      end if
   end do
   if( k == 1 ) then
      b(i) = a(i)
   else
      b(i) = 0
   end if
end do
j = 0
do i = 1,  n
   if( b(i) /= 0 ) then
      j = j + 1
   end if   
end do
write(*,'(i0)')  j

end program main