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 i,j,n,k,s:longint;
	a:array[-5..100050]of longint;

procedure kp(l,r:longint);
var c,d,e,f:longint;
begin
	c:=l;d:=r;e:=a[(l+r) div 2];
	repeat
		while a[c]<e do inc(c);
		while a[d]>e do dec(d);
		if c<=d then begin
			f:=a[c];a[c]:=a[d];a[d]:=f;
			inc(c);
			dec(d);
		end;
	until c>d;
	if c<r then kp(c,r);
	if l<d then kp(l,d);
end;
begin
	readln(n);
	for i:=1 to n do readln(a[i]);
	kp(1,n);
	s:=0;i:=0;
	repeat
		inc(i);k:=a[i];j:=1;
		while a[i+1]=k do begin
			inc(j);inc(i);
		end;
		if j mod 2=0 then else inc(s);
	until i=n;
	writeln(s);
end.