import java.util.*;

class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int n = Integer.parseInt(scanner.nextLine());

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

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

        Set<Integer> set = new HashSet<>();
        for (int i = 0; i < n; i++) {
            int a = Integer.parseInt(scanner.nextLine());
            set.add(a);
        }
        System.out.println(set.size());
    } main {
        Scanner scanner = new Scanner(System.in);
        int n = Integer.parseInt(scanner.nextLine());

        Set<Integer> set = new HashSet<>();
        for (int i = 0; i < n; i++) {
            int a = Integer.parseInt(scanner.nextLine());
            set.add(a);
        }
        System.out.println(set.size());
    } Scanner scanner = new Scanner(System.in); scanner new Scanner(System.in) int n = Integer.parseInt(scanner.nextLine()); n Integer.parseInt(scanner.nextLine()) Integer.parseInt Integer scanner.nextLine() scanner.nextLine scanner Set<Integer> set = new HashSet<>(); set new HashSet<>() for (int i = 0; i < n; i++) {
            int a = Integer.parseInt(scanner.nextLine());
            set.add(a);
        } int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
            int a = Integer.parseInt(scanner.nextLine());
            set.add(a);
        } {
            int a = Integer.parseInt(scanner.nextLine());
            set.add(a);
        } int a = Integer.parseInt(scanner.nextLine()); a Integer.parseInt(scanner.nextLine()) Integer.parseInt Integer scanner.nextLine() scanner.nextLine scanner set.add(a) set.add set a System.out.println(set.size()) System.out.println System.out System System.out set.size() set.size set String[] args args
import java.util.*;

class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int n = Integer.parseInt(scanner.nextLine());

        Set<Integer> set = new HashSet<>();
        for (int i = 0; i < n; i++) {
            int a = Integer.parseInt(scanner.nextLine());
            set.add(a);
        }
        System.out.println(set.size());
    }
}
