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 Kotlin (1.0.0) (judge verdict: Accepted)


import java.util.Scanner
import java.util.TreeSet


//
fun _Do() {

    val N_ = scan.nextInt()
    var a = Array(N_,{0})
    for(i in 0 until N_)
        a[i] = scan.nextInt()
    
    //--------
    var t = TreeSet<Int>()
    
    for(i in a.indices){
        
        when(t.contains(a[i])){
            false -> t.add(a[i])
            else -> t.remove(a[i])
        }
    }

    println(t.count())
}

var scan = Scanner(System.`in`)

fun strings(N:Int):Array<String>{
    var _s = Array(N,{""})
    for (i in _s.indices) {
        _s[i] = scan.next()
    }
    return _s
}

fun ints(N:Int):Array<Int>{
    var _s = Array(N,{0})
    for (i in _s.indices) {
        _s[i] = scan.nextInt()
    }
    return _s
}

fun longs(N:Int):Array<Long>{
    var _s = Array<Long>(N,{0})
    for (i in _s.indices) {
        _s[i] = scan.nextLong()
    }
    return _s
}
//
fun main( argv : Array<String> ) {
    _Do()
}