#include <iostream>
#include <vector>
#include <algorithm>

#define rep(i, n) for (int i = 0; i < n; i++)
#define all(x) x.begin(), x.end()

using namespace std;

int main()
{
	int n;
	cin >> n;

	vector<int> A(n);

	rep(i, n)
	{
		cin >> A[i];
	}
	sort(all(A));

	int ans = 0;
	bool flg = false;
	rep(i, n)
	{
		if (!flg && (i == n || A[i] != A[i + 1]))
		{
			ans++;
		}
		if (i != n)
		{
			flg = A[i] == A[i + 1] ? true : false;
		}
	}
	cout << ans << endl;
}