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: Accepted)

#include <limits.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

// 内部定数
#define D_ARRAY_MAX		100000									// 最大配列数

// 内部変数
static int si1Array[D_ARRAY_MAX + 5];							// 配列
static int siACnt;												// 配列数

// 内部変数 - テスト用
#ifdef D_TEST
	static int siRes;
	static FILE *szpFpT, *szpFpA;
#endif

// ソート関数 - int昇順
int
fSortFnc(
	const void *pzpVal1			// <I> 値１
	, const void *pzpVal2		// <I> 値２
)
{
	int *lipVal1 = (int *)pzpVal1;
	int *lipVal2 = (int *)pzpVal2;

	// 昇順
	if (*lipVal1 >  *lipVal2) {
		return(1);
	}
	else if (*lipVal1 < *lipVal2) {
		return(-1);
	}

	return 0;
}

// 実行メイン
int
fMain(
	int piTNo					// <I> テスト番号 1～
)
{
	int i;
	char lc1Buf[1024], lc1Out[1024];

	// テストファイルオープン
#ifdef D_TEST
	sprintf(lc1Buf, ".\\Test\\T%d.txt", piTNo);
	szpFpT = fopen(lc1Buf, "r");
	sprintf(lc1Buf, ".\\Test\\A%d.txt", piTNo);
	szpFpA = fopen(lc1Buf, "r");
	siRes = 0;
#endif

	// 配列数取得
#ifdef D_TEST
	fgets(lc1Buf, sizeof(lc1Buf), szpFpT);
#else
	fgets(lc1Buf, sizeof(lc1Buf), stdin);
#endif
	sscanf(lc1Buf, "%d", &siACnt);

	// 配列取得
	for (i = 0; i < siACnt; i++) {
#ifdef D_TEST
		fgets(lc1Buf, sizeof(lc1Buf), szpFpT);
#else
		fgets(lc1Buf, sizeof(lc1Buf), stdin);
#endif
		sscanf(lc1Buf, "%d", &si1Array[i]);
	}

	// ソート
	qsort(si1Array, siACnt, sizeof(int), fSortFnc);

	// 番兵追加
	si1Array[siACnt] = INT_MAX;

	// 奇数個の数字の数を取得
	int liSum = 0;
	int liCnt = 1;
	for (i = 1; i <= siACnt; i++) {
		if (si1Array[i] == si1Array[i - 1]) {	// １つ前と同じ
			liCnt++;
		}
		else {									// １つ前と違う
			if (liCnt % 2 == 1) {					// 奇数個
				liSum++;
			}
			liCnt = 1;
		}
	}

	// 結果セット
	sprintf(lc1Out, "%d\n", liSum);

	// 結果表示
#ifdef D_TEST
	fgets(lc1Buf, sizeof(lc1Buf), szpFpA);
	if (strcmp(lc1Buf, lc1Out)) {
		siRes = -1;
	}
#else
	printf("%s", lc1Out);
#endif

	// テストファイルクローズ
#ifdef D_TEST
	fclose(szpFpT);
	fclose(szpFpA);
#endif

	// テスト結果
#ifdef D_TEST
	if (siRes == 0) {
		printf("OK %d\n", piTNo);
	}
	else {
		printf("NG %d\n", piTNo);
	}
#endif

	return 0;
}

int
main()
{

#ifdef D_TEST
	int i;
	for (i = D_TEST_SNO; i <= D_TEST_ENO; i++) {
		fMain(i);
	}
#else
	fMain(0);
#endif

	return 0;
}