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 C++14 (GCC 5.4.1) (judge verdict: Accepted)

#include<bits/stdc++.h>
using namespace std;
char str[100];
inline int max(const int &a,const int &b){return a>b?a:b;}
inline int min(const int &a,const int &b){return a<b?a:b;}
inline void read(int &n)
{
	n=0;char c=getchar();bool b=0;
	while(c<'0'||c>'9'){if(c=='-')b=1;c=getchar();}
	while(c>='0'&&c<='9') n=(n<<3)+(n<<1)+c-48,c=getchar();
	if(b) n=-n;
}
set<int> s;
int n,x;
int main()
{
	read(n);
	for(int i=1;i<=n;i++)
	{
		read(x);
		if(s.find(x)!=s.end()) s.erase(x);
		else s.insert(x);
	}
	printf("%d",s.size());
}