import java.util.HashSet;
import java.util.Scanner;
import java.util.Set;

public class Main {
	public static void main(String[] args) {
		new Main().solve();
		return;
	}

	private void solve() {
		// 入力
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		Set<Integer> d = new HashSet<Integer>();
		for (int i = 0; i < N; i++) {
			d.add(sc.nextInt());
		}
		sc.close();

		// 出力
		System.out.println(d.size());

		return;
	}
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz