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 Python (3.4.3) (judge verdict: Wrong Answer)

#!/usr/bin/env python

def main():
    N = int(input())

    num_list = [] 
    for _ in range(N):
        num = int(input())
        num_list.append(num)

    num_list.sort()

    sum = 0
    cnt_same_num = 0
    prev_same_num = -1
    for n in num_list:
        if prev_same_num == n:
            cnt_same_num += 1
        else:
            if cnt_same_num % 2 == 1:
                sum += 1
            cnt_same_num = 1
            prev_same_num = n
    print(sum)

        

if __name__ == '__main__':
    main()