import java.io.PrintWriter;
import java.util.*;
public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		PrintWriter out = new PrintWriter(System.out);
		int N = Integer.parseInt(sc.next());
		int d[] = new int[N];
		for (int i = 0; i < N; i++) {
			d[i] = Integer.parseInt(sc.next());
		}

		int result = Arrays.stream(d).distinct().toArray().length;
		out.println(result);
		out.flush();
	}
} import java.io.PrintWriter; PrintWriter java.io import java.util.*; util.* java public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		PrintWriter out = new PrintWriter(System.out);
		int N = Integer.parseInt(sc.next());
		int d[] = new int[N];
		for (int i = 0; i < N; i++) {
			d[i] = Integer.parseInt(sc.next());
		}

		int result = Arrays.stream(d).distinct().toArray().length;
		out.println(result);
		out.flush();
	}
} Main public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		PrintWriter out = new PrintWriter(System.out);
		int N = Integer.parseInt(sc.next());
		int d[] = new int[N];
		for (int i = 0; i < N; i++) {
			d[i] = Integer.parseInt(sc.next());
		}

		int result = Arrays.stream(d).distinct().toArray().length;
		out.println(result);
		out.flush();
	} main {
		Scanner sc = new Scanner(System.in);
		PrintWriter out = new PrintWriter(System.out);
		int N = Integer.parseInt(sc.next());
		int d[] = new int[N];
		for (int i = 0; i < N; i++) {
			d[i] = Integer.parseInt(sc.next());
		}

		int result = Arrays.stream(d).distinct().toArray().length;
		out.println(result);
		out.flush();
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) PrintWriter out = new PrintWriter(System.out); out new PrintWriter(System.out) int N = Integer.parseInt(sc.next()); N Integer.parseInt(sc.next()) Integer.parseInt Integer sc.next() sc.next sc int d[] = new int[N]; d new int[N] N for (int i = 0; i < N; i++) {
			d[i] = Integer.parseInt(sc.next());
		} int i = 0; int i = 0; i 0 i < N i N i++ i++ i {
			d[i] = Integer.parseInt(sc.next());
		} {
			d[i] = Integer.parseInt(sc.next());
		} d[i] = Integer.parseInt(sc.next()) d[i] d i Integer.parseInt(sc.next()) Integer.parseInt Integer sc.next() sc.next sc int result = Arrays.stream(d).distinct().toArray().length; result Arrays.stream(d).distinct().toArray().length Arrays.stream(d).distinct().toArray() Arrays.stream(d).distinct().toArray Arrays.stream(d).distinct() Arrays.stream(d).distinct Arrays.stream(d) Arrays.stream Arrays d Arrays.stream(d).distinct().toArray().length out.println(result) out.println out result out.flush() out.flush out String[] args args public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		PrintWriter out = new PrintWriter(System.out);
		int N = Integer.parseInt(sc.next());
		int d[] = new int[N];
		for (int i = 0; i < N; i++) {
			d[i] = Integer.parseInt(sc.next());
		}

		int result = Arrays.stream(d).distinct().toArray().length;
		out.println(result);
		out.flush();
	}
} public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		PrintWriter out = new PrintWriter(System.out);
		int N = Integer.parseInt(sc.next());
		int d[] = new int[N];
		for (int i = 0; i < N; i++) {
			d[i] = Integer.parseInt(sc.next());
		}

		int result = Arrays.stream(d).distinct().toArray().length;
		out.println(result);
		out.flush();
	}
} Main
import java.io.PrintWriter;
import java.util.*;
public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		PrintWriter out = new PrintWriter(System.out);
		int N = Integer.parseInt(sc.next());
		int d[] = new int[N];
		for (int i = 0; i < N; i++) {
			d[i] = Integer.parseInt(sc.next());
		}

		int result = Arrays.stream(d).distinct().toArray().length;
		out.println(result);
		out.flush();
	}
}