import java.util.*;

class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        List<Integer> list = new ArrayList<>();
        for(int i = 0 ; i < n ; i ++){
          list.add(sc.nextInt());
        }
		 List<Integer> listB = new ArrayList<Integer>(new HashSet<>(list));
      
      	 System.out.print(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