#define _USE_MATH_DEFINES

#include <iostream>		//cin, cout
#include <vector>		//vector
#include <algorithm>	//sort,min,max,count
#include <string>		//string,getline, to_string
#include <cstdlib>		//abs(int)
#include <utility>		//swap, pair
#include <deque>		//deque
#include <climits>		//INT_MAX
#include <bitset>		//bitset
#include <cmath>		//sqrt, ceil. M_PI, pow, sin
#include <ios>			//fixed
#include <iomanip>		//setprecision
#include <sstream>		//stringstream
#include <numeric>		//gcd, assumlate
#include <random>		//randam_device
#include <limits>		//numeric_limits

using namespace std;
constexpr long long int D_MOD = 1000000007;

int main() {

	int N;
	cin >> N;

	vector<int> A, B;

	for (int i = 0; i < N; i++) {
		int temp;
		bool flg1 = true;
		cin >> temp;
		for (unsigned int j = 0; j < A.size(); j++) {
			if (A[j] == temp) {
				flg1 = false;
				break;
			}
		}
		if (flg1) {
			A.push_back(temp);
		}
		else {
			bool flg2 = true;
			for (unsigned int j = 0; j < B.size(); j++) {
				if (B[j] == temp) {
					flg2 = false;
					break;
				}
			}
			if (flg2) {
				B.push_back(temp);
			}
		}
	}

	int ans = A.size() - B.size();
	cout << ans << endl;

	return 0;

}