import java.util.*;
public class Main {
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int num = sc.nextInt();
	ArrayList<Integer> list = new ArrayList<>();
	for(int i=0; i<num; i++){
		list.add(sc.nextInt());
	}
	List<Integer> listB = new ArrayList<Integer>(new LinkedHashSet<>(list));
	System.out.println(listB.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