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 Rust (1.15.1) (judge verdict: Accepted)

fn main(){
	let mut s = String::new();
	std::io::stdin().read_line(&mut s).unwrap();
	let n: usize = s.trim().parse().unwrap();
	let mut v: Vec<u32> = Vec::new();
	for i in 0..n {
		let mut s = String::new();
		std::io::stdin().read_line(&mut s).unwrap();
		let a: u32 = s.trim().parse().unwrap();
		v.push(a);
	}
	v.sort();
	let mut p = 0;
	let mut c = 1;
	let mut pc = v.len();
	for i in 0..v.len() {
		if v[i] != p {
			p = v[i];
			c = 1;
		} else if v[i] == p {
			c += 1;
		}
		if c % 2 == 0 {
			pc -= 2;
		}
	}
	println!("{}", pc);
}