import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        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();
        }
        int[] c = Arrays.stream(a).distinct().toArray();
        System.out.println(c.length);
    }
} import java.util.*; util.* java public class Main {
    public static void main(String[] args) throws Exception {
        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();
        }
        int[] c = Arrays.stream(a).distinct().toArray();
        System.out.println(c.length);
    }
} Main public static void main(String[] args) throws Exception {
        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();
        }
        int[] c = Arrays.stream(a).distinct().toArray();
        System.out.println(c.length);
    } 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();
        }
        int[] c = Arrays.stream(a).distinct().toArray();
        System.out.println(c.length);
    } 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 int[] c = Arrays.stream(a).distinct().toArray(); c Arrays.stream(a).distinct().toArray() Arrays.stream(a).distinct().toArray Arrays.stream(a).distinct() Arrays.stream(a).distinct Arrays.stream(a) Arrays.stream Arrays a System.out.println(c.length) System.out.println System.out System System.out c.length c c.length String[] args args public class Main {
    public static void main(String[] args) throws Exception {
        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();
        }
        int[] c = Arrays.stream(a).distinct().toArray();
        System.out.println(c.length);
    }
} public class Main {
    public static void main(String[] args) throws Exception {
        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();
        }
        int[] c = Arrays.stream(a).distinct().toArray();
        System.out.println(c.length);
    }
} Main
import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        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();
        }
        int[] c = Arrays.stream(a).distinct().toArray();
        System.out.println(c.length);
    }
}