#include<iostream>
#include<cstdio>
#include<vector>
using namespace std;

int main() {
	int n, a[100001] = {};
	scanf("%d", &n);
	vector<int> b(n);
	for (int i = 0; i < n; i++)
	{
		cin >> b[i];
		a[b[i]] += 1;
	}

	int ans = 0;
	for (auto i = b.begin(); i != b.end(); i++)
	{
		if (a[*i] == 1)
		{
			ans++;
		}
	}
	cout << ans << endl;

	return 0;
}