import java.util.*;

public class Main {
  public static void main(String[] args ) throws Exception {
    Scanner sc = new Scanner(System.in);
    int N = sc.nextInt();
    
    List<Integer> as = new ArrayList<>();
    
    for(int i = 0; i < N; i++) {
        as.add(sc.nextInt());
    }
    List<Integer> as2 = new ArrayList<>(new HashSet<>(as));
    System.out.println(as2.size());
  }
} import java.util.*; util.* java public class Main {
  public static void main(String[] args ) throws Exception {
    Scanner sc = new Scanner(System.in);
    int N = sc.nextInt();
    
    List<Integer> as = new ArrayList<>();
    
    for(int i = 0; i < N; i++) {
        as.add(sc.nextInt());
    }
    List<Integer> as2 = new ArrayList<>(new HashSet<>(as));
    System.out.println(as2.size());
  }
} Main public static void main(String[] args ) throws Exception {
    Scanner sc = new Scanner(System.in);
    int N = sc.nextInt();
    
    List<Integer> as = new ArrayList<>();
    
    for(int i = 0; i < N; i++) {
        as.add(sc.nextInt());
    }
    List<Integer> as2 = new ArrayList<>(new HashSet<>(as));
    System.out.println(as2.size());
  } main {
    Scanner sc = new Scanner(System.in);
    int N = sc.nextInt();
    
    List<Integer> as = new ArrayList<>();
    
    for(int i = 0; i < N; i++) {
        as.add(sc.nextInt());
    }
    List<Integer> as2 = new ArrayList<>(new HashSet<>(as));
    System.out.println(as2.size());
  } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int N = sc.nextInt(); N sc.nextInt() sc.nextInt sc List<Integer> as = new ArrayList<>(); as new ArrayList<>() for(int i = 0; i < N; i++) {
        as.add(sc.nextInt());
    } int i = 0; int i = 0; i 0 i < N i N i++ i++ i {
        as.add(sc.nextInt());
    } {
        as.add(sc.nextInt());
    } as.add(sc.nextInt()) as.add as sc.nextInt() sc.nextInt sc List<Integer> as2 = new ArrayList<>(new HashSet<>(as)); as2 new ArrayList<>(new HashSet<>(as)) System.out.println(as2.size()) System.out.println System.out System System.out as2.size() as2.size as2 String[] args args public class Main {
  public static void main(String[] args ) throws Exception {
    Scanner sc = new Scanner(System.in);
    int N = sc.nextInt();
    
    List<Integer> as = new ArrayList<>();
    
    for(int i = 0; i < N; i++) {
        as.add(sc.nextInt());
    }
    List<Integer> as2 = new ArrayList<>(new HashSet<>(as));
    System.out.println(as2.size());
  }
} public class Main {
  public static void main(String[] args ) throws Exception {
    Scanner sc = new Scanner(System.in);
    int N = sc.nextInt();
    
    List<Integer> as = new ArrayList<>();
    
    for(int i = 0; i < N; i++) {
        as.add(sc.nextInt());
    }
    List<Integer> as2 = new ArrayList<>(new HashSet<>(as));
    System.out.println(as2.size());
  }
} Main
import java.util.*;

public class Main {
  public static void main(String[] args ) throws Exception {
    Scanner sc = new Scanner(System.in);
    int N = sc.nextInt();
    
    List<Integer> as = new ArrayList<>();
    
    for(int i = 0; i < N; i++) {
        as.add(sc.nextInt());
    }
    List<Integer> as2 = new ArrayList<>(new HashSet<>(as));
    System.out.println(as2.size());
  }
}
