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)

use std::vec::Vec;
use std::cmp::*;

fn read<T: std::str::FromStr>() -> T {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).ok();
    s.trim().parse().ok().unwrap()
}

fn read_vec<T: std::str::FromStr>() -> Vec<T> {
    read::<String>().split_whitespace().map(|e| e.parse().ok().unwrap()).collect()
}

fn count_same_element<T: Eq + Copy>(v: &Vec<T>) -> Vec<usize> {

  let mut res: Vec<usize> = Vec::new();
  if v.len() == 0 {
    return res;
  }

  let mut now: T = v[0];
  let mut count: usize = 0;
  for &e in v {
    if e == now {
      count += 1;
    }
    else {
      res.push(count);
      count = 1;
      now = e;
    }
  }
  res.push(count);

  return res;
}


fn main() {
  let n: usize = read();
  let mut a: Vec<u64> = Vec::new();
  for _ in 0..n {
    let c = read();
    a.push(c);
  }

  a.sort();

  let same = count_same_element(&a);
  let ans = same.iter().fold(0, |acc, x| acc + (x % 2));
  println!("{}", ans);
}