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
 n,i,x,s:longint;
 a:array[0..100001] of int64;
procedure kp(l,r:longint);
var
 i,j,t,m:longint;
begin
 i:=l; j:=r;
 m:=a[(l+r) div 2];
 repeat
  while a[i]<m do inc(i);
  while a[j]>m 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 l<j then kp(l,j);
 if i<r then kp(i,r);
end; 
begin
 readln(n);
 for i:=1 to n do 
  readln(a[i]);
 kp(1,n);
 x:=1;
 for i:=2 to n do
  if a[i]=a[i-1] then inc(x)
   else
    begin
     if odd(x) then inc(s);
     x:=1;
    end; 
 if odd(x) then inc(s);
 writeln(s);
end.