import java.util.*;

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

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        int n = Integer.parseInt(sc.next());
        HashSet<Integer> set = new HashSet<>();
        for (int i = 0; i < n; i++) {
            set.add(Integer.parseInt(sc.next()));
        }
        System.out.println(set.size());
    }
}
