import java.util.*;

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

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