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)

fun main(args: Array<String>) {
    val numN = readLine()?.orEmpty()
    val cardList = mutableListOf<Long>()
    val numList = mutableMapOf<Long,Int?>()
    for(i in 0 until numN!!.toInt()){
        val num = readLine()?.orEmpty()!!.toLong()
        if(!numList.containsKey(num)){
            numList[num] = 1
        }else{
            numList[num] = numList[num]?.plus(1)
        }
    }

    numList.forEach{
        val card = it.value
        if (card != null) {
            if(card % 2 != 0){
                cardList.add(it.key)
            }
        }
    }

    println(cardList.size)
}