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 Pascal (FPC 2.6.2) (judge verdict: Accepted)

var
  a:array[1..100001] of longint;
  n,i,s,sum:longint;
 procedure kp(l,r:longint);
  var
    i,j,t,mid:longint;
  begin
    i:=l; j:=r; mid:=a[(i+j) div 2];
    repeat
      while a[i]<mid do inc(i);
      while a[j]>mid do dec(j);
      if i<=j then
        begin
          t:=a[i]; a[i]:=a[j]; a[j]:=t;
          inc(i); dec(j);
        end;
    until i>j;
    if i<r then kp(i,r);
    if j>l then kp(l,j);
  end;
begin
  readln(n);
  for i:=1 to n do readln(a[i]);
  kp(1,n);
  s:=1;
  for i:=2 to n+1 do
    if a[i]=a[i-1] then inc(s)
      else
        begin
          if odd(s) then inc(sum);
          s:=1;
        end;
  writeln(sum);
end.