#abc073c. [abc073_c]Write and Erase
[abc073_c]Write and Erase
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 times.
- Then, you are asked a question: How many numbers are written on the sheet now?
The numbers announced by Joisino are given as in the order she announces them. How many numbers will be written on the sheet at the end of the game?
Constraints
- All input values are integers.
Input
Input is given from Standard Input in the following format:
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:
-
is not written on the sheet, so write .
-
is not written on the sheet, so write .
-
is written on the sheet, so erase .
Thus, the sheet contains only in the end. The answer is .
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