import java.util.*;
import java.util.stream.Collectors;

class Main {
    public static void main(String args[]) {
        Scanner sc = new Scanner(System.in);
      
        int n = sc.nextInt();
        Set<Integer> mochiSet = new HashSet<>();
        for(int i = 0;i < n; i++) {
            mochiSet.add(sc.nextInt());
        }

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

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

        System.out.println(mochiSet.size());
    } main {
        Scanner sc = new Scanner(System.in);
      
        int n = sc.nextInt();
        Set<Integer> mochiSet = new HashSet<>();
        for(int i = 0;i < n; i++) {
            mochiSet.add(sc.nextInt());
        }

        System.out.println(mochiSet.size());
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int n = sc.nextInt(); n sc.nextInt() sc.nextInt sc Set<Integer> mochiSet = new HashSet<>(); mochiSet new HashSet<>() for(int i = 0;i < n; i++) {
            mochiSet.add(sc.nextInt());
        } int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
            mochiSet.add(sc.nextInt());
        } {
            mochiSet.add(sc.nextInt());
        } mochiSet.add(sc.nextInt()) mochiSet.add mochiSet sc.nextInt() sc.nextInt sc System.out.println(mochiSet.size()) System.out.println System.out System System.out mochiSet.size() mochiSet.size mochiSet String args[] args
import java.util.*;
import java.util.stream.Collectors;

class Main {
    public static void main(String args[]) {
        Scanner sc = new Scanner(System.in);
      
        int n = sc.nextInt();
        Set<Integer> mochiSet = new HashSet<>();
        for(int i = 0;i < n; i++) {
            mochiSet.add(sc.nextInt());
        }

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