import java.util.*;
 
public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        int[] a = new int[N];
        
        for(int i=0; i<N; i++){
            a[i] = sc.nextInt();
        }
        
        TreeSet <Integer> tree = new TreeSet <Integer> ();
        for(int i=0; i<N; i++){
            tree.add(new Integer(a[i]));
        }
        System.out.println(tree.size());
    }
} import java.util.*; util.* java public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        int[] a = new int[N];
        
        for(int i=0; i<N; i++){
            a[i] = sc.nextInt();
        }
        
        TreeSet <Integer> tree = new TreeSet <Integer> ();
        for(int i=0; i<N; i++){
            tree.add(new Integer(a[i]));
        }
        System.out.println(tree.size());
    }
} Main public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        int[] a = new int[N];
        
        for(int i=0; i<N; i++){
            a[i] = sc.nextInt();
        }
        
        TreeSet <Integer> tree = new TreeSet <Integer> ();
        for(int i=0; i<N; i++){
            tree.add(new Integer(a[i]));
        }
        System.out.println(tree.size());
    } main {
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        int[] a = new int[N];
        
        for(int i=0; i<N; i++){
            a[i] = sc.nextInt();
        }
        
        TreeSet <Integer> tree = new TreeSet <Integer> ();
        for(int i=0; i<N; i++){
            tree.add(new Integer(a[i]));
        }
        System.out.println(tree.size());
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int N = sc.nextInt(); N sc.nextInt() sc.nextInt sc int[] a = new int[N]; a new int[N] N for(int i=0; i<N; i++){
            a[i] = sc.nextInt();
        } int i=0; int i=0; i 0 i<N i N i++ i++ i {
            a[i] = sc.nextInt();
        } {
            a[i] = sc.nextInt();
        } a[i] = sc.nextInt() a[i] a i sc.nextInt() sc.nextInt sc TreeSet <Integer> tree = new TreeSet <Integer> (); tree new TreeSet <Integer> () for(int i=0; i<N; i++){
            tree.add(new Integer(a[i]));
        } int i=0; int i=0; i 0 i<N i N i++ i++ i {
            tree.add(new Integer(a[i]));
        } {
            tree.add(new Integer(a[i]));
        } tree.add(new Integer(a[i])) tree.add tree new Integer(a[i]) System.out.println(tree.size()) System.out.println System.out System System.out tree.size() tree.size tree String[] args args public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        int[] a = new int[N];
        
        for(int i=0; i<N; i++){
            a[i] = sc.nextInt();
        }
        
        TreeSet <Integer> tree = new TreeSet <Integer> ();
        for(int i=0; i<N; i++){
            tree.add(new Integer(a[i]));
        }
        System.out.println(tree.size());
    }
} public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        int[] a = new int[N];
        
        for(int i=0; i<N; i++){
            a[i] = sc.nextInt();
        }
        
        TreeSet <Integer> tree = new TreeSet <Integer> ();
        for(int i=0; i<N; i++){
            tree.add(new Integer(a[i]));
        }
        System.out.println(tree.size());
    }
} Main
import java.util.*;
 
public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        int[] a = new int[N];
        
        for(int i=0; i<N; i++){
            a[i] = sc.nextInt();
        }
        
        TreeSet <Integer> tree = new TreeSet <Integer> ();
        for(int i=0; i<N; i++){
            tree.add(new Integer(a[i]));
        }
        System.out.println(tree.size());
    }
}