import java.util.*;

public class Main{
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int N = sc.nextInt();
    ArrayList<Integer> d = new ArrayList<Integer>();
    for (int i=0; i<N; i++) {
      d.add(sc.nextInt());
    }
    int ans = new HashSet<>(d).size();
    System.out.println(ans);
  }
}
/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