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 C (GCC 5.4.1) (judge verdict: Wrong Answer)

/*joisinoお姉ちゃんは、劇場の受付を担当しています。

この劇場には、席 1 から席 100000 までの、100000 個の席があります。

彼女のメモ書きによると、今までの間に N 組の団体が来て、i 組目の団体は席 li から席 ri までの連続した席に座っています。

今、劇場の席には何人座っているか求めてください。

制約
1≦N≦1000
1≦li≦ri≦100000
同じ席に複数の人が座ることはない。
入力は全て整数である。
入力
入力は以下の形式で標準入力から与えられる。

N
l1 r1
	:
lN rN
*/

#include <stdio.h>

int main(void) {
	int n,sum=0;
	unsigned int a[100001] = {0};
	int t;
	scanf(" %d", &n);
	for (int i = 0; i < n; i++) {
		int x;
		scanf(" %d",&x);
		for (t = 0; t < 100001; t++) {
			if (a[t] == x) {
				a[t] = 0;
				break;
			}
			//else {

			//}
			if (a[t]==0) {
				a[t] = x;
				break;
			}
		}
	}
	for (t = 0; t < 100001; t++) {
		if (a[t] != 0) {
			sum++;
		}
	}

	printf("%d", sum);


	return 0;
}