#include <iostream>
using namespace std;

int main(void){
//input
	int N; cin >> N;
	int a[N]; for(int i=0;i<N;i++){ cin >> a[i]; }
//calc
	int cnt=0; bool newFlg;
	for(int i=0;i<N;i++){
		newFlg = true;
		for(int j=0;j<N;j++){
			if(j == i){
				continue;
			}else{
				if(a[j] == a[i]){
					newFlg = false;
					break;
				}
			}
		}
		if(newFlg) cnt++;
	}
//output
	cout << cnt << endl;
}