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: Accepted)

integer(16)N
integer(16),allocatable,dimension(:)::A
integer(16)tmp,tmpcnt,ans
read*,N
allocate(A(N))
do i=1,N
  read*,A(i)
end do
call heapsort(N,A)
tmp=0;tmpcnt=0;ans=0
do i=1,N
  if(A(i)==tmp)then
    tmpcnt=xor(tmpcnt,1)
  else
    ans=ans+tmpcnt
    tmp=A(i)
    tmpcnt=1
   endif
end do
ans=ans+tmpcnt
print"(i0)",ans
contains
subroutine heapsort(n,array)
  implicit none
!ここの入力は状況に応じて変更すること
  integer(16),intent(in) :: n
  integer(16),intent(inout) :: array(1:n)
  integer(16)::i,k,j,l
  integer(16):: t

  l=n/2+1
  k=n
  do while(k /= 1)
     if(l > 1)then
        l=l-1
        t=array(L)
     else
        t=array(k)
        array(k)=array(1)
        k=k-1
        if(k == 1) then
           array(1)=t
           exit
        endif
     endif
     i=l
     j=l+l
     do while(j<=k)
        if(j < k)then
           if(array(j) < array(j+1))j=j+1
        endif
        if (t < array(j))then
           array(i)=array(j)
           i=j
           j=j+j
        else
           j=k+1
        endif
     enddo
     array(i)=t
  enddo
  return
end subroutine heapsort
end