100732: [AtCoder]ABC073 C - Write and Erase

Memory Limit:256 MB Time Limit:2 S
Judge Style:Text Compare Creator:
Submit:1 Solved:0

Description

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

Input

题意翻译

给你一个空序列,以及$N$个询问$Ai$,如在序列中有这个数,就将序列中的数删去,如在序列中没有这个数,就将这个数加入序列中,问最后序列中的元素个数为多少。 #### 数据范围 $1≤N≤100000$,$1≤Ai≤1000000000(=10^9)$

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