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

using namespace std;

int main()
{
	int N;
	cin >> N;
	vector<int> A( N, 0 );

	for( int i = 0; i < N; i++ ) {
		cin >> A[i];
	}
	sort( A.begin(), A.end() );
	int cnt = 0;
	int shin  = 1;
	int before = A[0];
	for( int i = 1; i < N; i++ ) {
		if( before == A[i] ) {
			shin++;
		}
		else {
			if( shin == 1 ) {
				cnt ++;
			}
			shin = 1;
			before = A[i];
		}
	}
	if( shin == 1 ) {
		cnt++;
	}
	cout << cnt << endl;
	return 0;
}