import java.util.HashSet;
import java.util.Scanner;
import java.util.Set;

public class Main {
    public static void main(String[] args) {
    	Scanner sc = new Scanner(System.in);
    	int N = Integer.parseInt(sc.next());
    	Set<Integer> a = new HashSet<Integer>();

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

    	System.out.println(a.size());
    }
} import java.util.HashSet; HashSet java.util import java.util.Scanner; Scanner java.util import java.util.Set; Set java.util public class Main {
    public static void main(String[] args) {
    	Scanner sc = new Scanner(System.in);
    	int N = Integer.parseInt(sc.next());
    	Set<Integer> a = new HashSet<Integer>();

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

    	System.out.println(a.size());
    }
} Main public static void main(String[] args) {
    	Scanner sc = new Scanner(System.in);
    	int N = Integer.parseInt(sc.next());
    	Set<Integer> a = new HashSet<Integer>();

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

    	System.out.println(a.size());
    } main {
    	Scanner sc = new Scanner(System.in);
    	int N = Integer.parseInt(sc.next());
    	Set<Integer> a = new HashSet<Integer>();

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

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

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

    	System.out.println(a.size());
    }
} public class Main {
    public static void main(String[] args) {
    	Scanner sc = new Scanner(System.in);
    	int N = Integer.parseInt(sc.next());
    	Set<Integer> a = new HashSet<Integer>();

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

    	System.out.println(a.size());
    }
} Main
import java.util.HashSet;
import java.util.Scanner;
import java.util.Set;

public class Main {
    public static void main(String[] args) {
    	Scanner sc = new Scanner(System.in);
    	int N = Integer.parseInt(sc.next());
    	Set<Integer> a = new HashSet<Integer>();

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

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