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 (1.42.0) (judge verdict: Accepted)

#![allow(non_snake_case)]
#![allow(unused_macros)]
#![allow(unused_imports)]

use proconio::marker::Usize1;
use proconio::{fastout, input};
use std::vec::*;

macro_rules! echo {
  {$x:expr} => {println!("{}", $x)}
}

macro_rules! chmax {
  {$x:expr, $y:expr} => {
    $x = std::cmp::max($x, $y)
  }
}

macro_rules! chmin {
  {$x:expr, $y:expr} => {
    $x = std::cmp::min($x, $y)
  }
}

#[allow(unused_variables)]
#[fastout]
fn main() {
  let n: usize;
  let a: Vec<usize>;
  input! {
    n: usize,
    a: [usize; n]
  }
  let mut nanachi = a.clone();
  nanachi.sort();
  nanachi.dedup();
  let mut aa = vec![false; nanachi.len()];
  for i in a.into_iter().map(|x| nanachi.binary_search(&x).unwrap()) {
    aa[i] = !aa[i];
  }
  echo!(aa.into_iter().filter(|&x| x).count());
}