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++14 (GCC 5.4.1) (judge verdict: Accepted)

#include <iostream>
#include <vector>
#include <set>
#include <algorithm>
#include <string>
#include <cmath>
#include <iomanip>
#include <map>
#include <set>
#include <numeric>
#include <queue>
using namespace std;
#define loop(i,N) for(ll (i)=0; (i)<(N);++(i))
struct TEMP_OMAZINAI_ { TEMP_OMAZINAI_() { std::ios::sync_with_stdio(false); std::cin.tie(0); } } TEMP__omazinai_instance__;
#define INF ((1LL<<61) + (1<<29))
#define YesNo(x) {std::cout << ((x)?"Yes":"No") << std::endl;}
#define YESNO(x) {std::cout << ((x)?"YES":"NO") << std::endl;}
#define OddEven(x) {std::cout << ((x)%2?"Odd":"Even") << std::endl;}
#define ODDEVEN(x) {std::cout << ((x)%2?"ODD":"EVEN") << std::endl;}
typedef long long int ll;
ll my_gcd(ll a, ll b) { return b ? my_gcd(b, a%b) : a; };
void TEMP_INPUT_IMPL_() {};
template <class T, class... Args> void TEMP_INPUT_IMPL_(T& dest, Args&... args) { cin >> dest; TEMP_INPUT_IMPL_(args...); }
void TEMP_OUTPUT_IMPL_() {};
template <class T, class... Args> void TEMP_OUTPUT_IMPL_(T dest, Args... args) { cout << dest << (sizeof...(Args) ? " " : ""); TEMP_OUTPUT_IMPL_(args...); }
#define in(type, ...) type __VA_ARGS__; TEMP_INPUT_IMPL_(__VA_ARGS__)
#define in_v(type, name, cnt) vector<type> name(cnt); loop(i, cnt) cin >> name[i];
#define sort_v(v) std::sort(v.begin(), v.end())
#define unique_v(v) v.erase(std::unique(v.begin(), v.end()), v.end()) //必ずソート後に実行
#define out(...) (TEMP_OUTPUT_IMPL_(__VA_ARGS__), std::cout<<std::endl)
#define set_fix(x) ((std::cerr<<std::fixed<<std::setprecision(x)),(std::cout<<std::fixed<<std::setprecision(x)))
//小さい方に寄る
#define space_op(x, y, a, b, c) ([](auto x_, auto y_, auto a_, auto b_, auto c_){if(x_<y_)return a_;if(x_>y_)return c_;return b_;}(x,y,a,b,c))
#define space_out(x, y, a, b, c) out(space_op(x, y, a, b, c))
 
 // ^^^ Template ^^^ //

#include <stack>
int main() {
	in(ll, N);
	in_v(ll, A, N);
	if(N) sort_v(A);
	stack<ll> t;
	for(ll a : A){
		if(!t.empty() && t.top() == a)
			t.pop();
		else
			t.push(a);
	}
	cout << t.size() << endl;
}