import java.util.*;

public class Main {
    public static void main(String[] args) {
        int N = 0;
        Scanner scanner = new Scanner(System.in);

        Set<Integer> numbers = new HashSet<>();
        N = Integer.parseInt(scanner.next());

        for (int i = 0; i < N; i++) {
            numbers.add(Integer.parseInt(scanner.next()));
        }

        System.out.println(numbers.size());
    }
} import java.util.*; util.* java public class Main {
    public static void main(String[] args) {
        int N = 0;
        Scanner scanner = new Scanner(System.in);

        Set<Integer> numbers = new HashSet<>();
        N = Integer.parseInt(scanner.next());

        for (int i = 0; i < N; i++) {
            numbers.add(Integer.parseInt(scanner.next()));
        }

        System.out.println(numbers.size());
    }
} Main public static void main(String[] args) {
        int N = 0;
        Scanner scanner = new Scanner(System.in);

        Set<Integer> numbers = new HashSet<>();
        N = Integer.parseInt(scanner.next());

        for (int i = 0; i < N; i++) {
            numbers.add(Integer.parseInt(scanner.next()));
        }

        System.out.println(numbers.size());
    } main {
        int N = 0;
        Scanner scanner = new Scanner(System.in);

        Set<Integer> numbers = new HashSet<>();
        N = Integer.parseInt(scanner.next());

        for (int i = 0; i < N; i++) {
            numbers.add(Integer.parseInt(scanner.next()));
        }

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

        Set<Integer> numbers = new HashSet<>();
        N = Integer.parseInt(scanner.next());

        for (int i = 0; i < N; i++) {
            numbers.add(Integer.parseInt(scanner.next()));
        }

        System.out.println(numbers.size());
    }
} public class Main {
    public static void main(String[] args) {
        int N = 0;
        Scanner scanner = new Scanner(System.in);

        Set<Integer> numbers = new HashSet<>();
        N = Integer.parseInt(scanner.next());

        for (int i = 0; i < N; i++) {
            numbers.add(Integer.parseInt(scanner.next()));
        }

        System.out.println(numbers.size());
    }
} Main
import java.util.*;

public class Main {
    public static void main(String[] args) {
        int N = 0;
        Scanner scanner = new Scanner(System.in);

        Set<Integer> numbers = new HashSet<>();
        N = Integer.parseInt(scanner.next());

        for (int i = 0; i < N; i++) {
            numbers.add(Integer.parseInt(scanner.next()));
        }

        System.out.println(numbers.size());
    }
}