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



//----------------------------------------