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();

        for (int i = 0; i < N; i++) {
            d.add(sc.nextInt());
        }
        sc.close();
        System.out.println(d.stream().distinct().count());
    }
} import java.util.*; util.* java public class Main {
    public static void main(String... args) {
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        ArrayList<Integer> d = new ArrayList();

        for (int i = 0; i < N; i++) {
            d.add(sc.nextInt());
        }
        sc.close();
        System.out.println(d.stream().distinct().count());
    }
} Main public static void main(String... args) {
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        ArrayList<Integer> d = new ArrayList();

        for (int i = 0; i < N; i++) {
            d.add(sc.nextInt());
        }
        sc.close();
        System.out.println(d.stream().distinct().count());
    } main {
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        ArrayList<Integer> d = new ArrayList();

        for (int i = 0; i < N; i++) {
            d.add(sc.nextInt());
        }
        sc.close();
        System.out.println(d.stream().distinct().count());
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int N = sc.nextInt(); N sc.nextInt() sc.nextInt sc ArrayList<Integer> d = new ArrayList(); d new ArrayList() for (int i = 0; i < N; i++) {
            d.add(sc.nextInt());
        } int i = 0; int i = 0; i 0 i < N i N i++ i++ i {
            d.add(sc.nextInt());
        } {
            d.add(sc.nextInt());
        } d.add(sc.nextInt()) d.add d sc.nextInt() sc.nextInt sc sc.close() sc.close sc System.out.println(d.stream().distinct().count()) System.out.println System.out System System.out d.stream().distinct().count() d.stream().distinct().count d.stream().distinct() d.stream().distinct d.stream() d.stream d String... args args public class Main {
    public static void main(String... args) {
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        ArrayList<Integer> d = new ArrayList();

        for (int i = 0; i < N; i++) {
            d.add(sc.nextInt());
        }
        sc.close();
        System.out.println(d.stream().distinct().count());
    }
} public class Main {
    public static void main(String... args) {
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        ArrayList<Integer> d = new ArrayList();

        for (int i = 0; i < N; i++) {
            d.add(sc.nextInt());
        }
        sc.close();
        System.out.println(d.stream().distinct().count());
    }
} Main
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();

        for (int i = 0; i < N; i++) {
            d.add(sc.nextInt());
        }
        sc.close();
        System.out.println(d.stream().distinct().count());
    }
}