import java.util.*;

public class Main {

	public static void main(String... nui) {
		
		Scanner sc = new Scanner(System.in);
		
		Set<Integer> set = new HashSet<>();
		
		int n = sc.nextInt();
		
		for (int i = 0; i < n; i++) set.add(sc.nextInt());
		
		System.out.println(set.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