import java.util.*;

class Main {
    public static void main(final String[] args) {
      Scanner sc = new Scanner(System.in);
      int n = sc.nextInt();
      Set<Integer> d = new TreeSet<>();
      for (int i=0;i<n;i++) {
        int x = sc.nextInt();
        d.add(x);
      }
      System.out.println(d.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