import java.util.Scanner;
import java.util.TreeSet;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        TreeSet<Integer> t = new TreeSet<Integer>();
        for (int i = 1; i <= n; i++) {
            t.add(sc.nextInt());
        }
        System.out.println(t.size());
    }
} import java.util.Scanner; Scanner java.util import java.util.TreeSet; TreeSet java.util public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        TreeSet<Integer> t = new TreeSet<Integer>();
        for (int i = 1; i <= n; i++) {
            t.add(sc.nextInt());
        }
        System.out.println(t.size());
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        TreeSet<Integer> t = new TreeSet<Integer>();
        for (int i = 1; i <= n; i++) {
            t.add(sc.nextInt());
        }
        System.out.println(t.size());
    } main {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        TreeSet<Integer> t = new TreeSet<Integer>();
        for (int i = 1; i <= n; i++) {
            t.add(sc.nextInt());
        }
        System.out.println(t.size());
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int n = sc.nextInt(); n sc.nextInt() sc.nextInt sc TreeSet<Integer> t = new TreeSet<Integer>(); t new TreeSet<Integer>() for (int i = 1; i <= n; i++) {
            t.add(sc.nextInt());
        } int i = 1; int i = 1; i 1 i <= n i n i++ i++ i {
            t.add(sc.nextInt());
        } {
            t.add(sc.nextInt());
        } t.add(sc.nextInt()) t.add t sc.nextInt() sc.nextInt sc System.out.println(t.size()) System.out.println System.out System System.out t.size() t.size t String[] args args public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        TreeSet<Integer> t = new TreeSet<Integer>();
        for (int i = 1; i <= n; i++) {
            t.add(sc.nextInt());
        }
        System.out.println(t.size());
    }
} public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        TreeSet<Integer> t = new TreeSet<Integer>();
        for (int i = 1; i <= n; i++) {
            t.add(sc.nextInt());
        }
        System.out.println(t.size());
    }
} Main
import java.util.Scanner;
import java.util.TreeSet;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        TreeSet<Integer> t = new TreeSet<Integer>();
        for (int i = 1; i <= n; i++) {
            t.add(sc.nextInt());
        }
        System.out.println(t.size());
    }
}
