import java.util.Scanner;
import java.util.*;
public class Main{
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int a   = scan.nextInt();
        List<Integer> listA = new ArrayList<Integer>();

        for (int i = 0; i < a; i++) {
            listA.add(new Integer(scan.nextInt()));
        }

        List<Integer> listB = new ArrayList<Integer>(new LinkedHashSet<>(listA));

        System.out.println(listB.size());
    }
} import java.util.Scanner; Scanner java.util import java.util.*; util.* java public class Main{
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int a   = scan.nextInt();
        List<Integer> listA = new ArrayList<Integer>();

        for (int i = 0; i < a; i++) {
            listA.add(new Integer(scan.nextInt()));
        }

        List<Integer> listB = new ArrayList<Integer>(new LinkedHashSet<>(listA));

        System.out.println(listB.size());
    }
} Main public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int a   = scan.nextInt();
        List<Integer> listA = new ArrayList<Integer>();

        for (int i = 0; i < a; i++) {
            listA.add(new Integer(scan.nextInt()));
        }

        List<Integer> listB = new ArrayList<Integer>(new LinkedHashSet<>(listA));

        System.out.println(listB.size());
    } main {
        Scanner scan = new Scanner(System.in);
        int a   = scan.nextInt();
        List<Integer> listA = new ArrayList<Integer>();

        for (int i = 0; i < a; i++) {
            listA.add(new Integer(scan.nextInt()));
        }

        List<Integer> listB = new ArrayList<Integer>(new LinkedHashSet<>(listA));

        System.out.println(listB.size());
    } Scanner scan = new Scanner(System.in); scan new Scanner(System.in) int a   = scan.nextInt(); a scan.nextInt() scan.nextInt scan List<Integer> listA = new ArrayList<Integer>(); listA new ArrayList<Integer>() for (int i = 0; i < a; i++) {
            listA.add(new Integer(scan.nextInt()));
        } int i = 0; int i = 0; i 0 i < a i a i++ i++ i {
            listA.add(new Integer(scan.nextInt()));
        } {
            listA.add(new Integer(scan.nextInt()));
        } listA.add(new Integer(scan.nextInt())) listA.add listA new Integer(scan.nextInt()) List<Integer> listB = new ArrayList<Integer>(new LinkedHashSet<>(listA)); listB new ArrayList<Integer>(new LinkedHashSet<>(listA)) System.out.println(listB.size()) System.out.println System.out System System.out listB.size() listB.size listB String[] args args public class Main{
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int a   = scan.nextInt();
        List<Integer> listA = new ArrayList<Integer>();

        for (int i = 0; i < a; i++) {
            listA.add(new Integer(scan.nextInt()));
        }

        List<Integer> listB = new ArrayList<Integer>(new LinkedHashSet<>(listA));

        System.out.println(listB.size());
    }
} public class Main{
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int a   = scan.nextInt();
        List<Integer> listA = new ArrayList<Integer>();

        for (int i = 0; i < a; i++) {
            listA.add(new Integer(scan.nextInt()));
        }

        List<Integer> listB = new ArrayList<Integer>(new LinkedHashSet<>(listA));

        System.out.println(listB.size());
    }
} Main
import java.util.Scanner;
import java.util.*;
public class Main{
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int a   = scan.nextInt();
        List<Integer> listA = new ArrayList<Integer>();

        for (int i = 0; i < a; i++) {
            listA.add(new Integer(scan.nextInt()));
        }

        List<Integer> listB = new ArrayList<Integer>(new LinkedHashSet<>(listA));

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