import java.util.*;
public class Novelty{
	public static void main(String... args){
		Scanner scan = new Scanner(System.in);
		int n = scan.nextInt();
		System.out.println(counter(n,scan));
	}
	public static int counter(int n, Scanner scan){
		ArrayList<Integer> novelty = new ArrayList<Integer>();
		int count=0;
		for(int i = 0; i < n; i++){
			int now = scan.nextInt();
			novelty.add(now);
			if(novelty.indexOf(now) != -1){
				count++;
			}
		}
		return n-count;
	}
}