import java.util.*;
public class Main {
	public static void main(String args[]) {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		int d[] = new int[N];
		Map<Integer, Integer> map = new HashMap<Integer, Integer>();
		for(int i = 0; i < N; i++) {
			d[i] = sc.nextInt();
			map.put(d[i], 1);
		}
		System.out.println(map.size());
	}
}

/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