import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.HashSet;
import java.util.Scanner;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TaskB solver = new TaskB();
        solver.solve(1, in, out);
        out.close();
    }

    static class TaskB {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            int n = in.nextInt();
            HashSet<Integer> a = new HashSet<Integer>();

            for (int i = 0; i < n; i++) {
                a.add(in.nextInt());
            }


            out.print(a.size());
        }

    }
}
 import java.io.OutputStream; OutputStream java.io import java.io.IOException; IOException java.io import java.io.InputStream; InputStream java.io import java.io.PrintWriter; PrintWriter java.io import java.util.HashSet; HashSet java.util import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TaskB solver = new TaskB();
        solver.solve(1, in, out);
        out.close();
    }

    static class TaskB {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            int n = in.nextInt();
            HashSet<Integer> a = new HashSet<Integer>();

            for (int i = 0; i < n; i++) {
                a.add(in.nextInt());
            }


            out.print(a.size());
        }

    }
} Main public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TaskB solver = new TaskB();
        solver.solve(1, in, out);
        out.close();
    } main {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TaskB solver = new TaskB();
        solver.solve(1, in, out);
        out.close();
    } InputStream inputStream = System.in; inputStream System.in System System.in OutputStream outputStream = System.out; outputStream System.out System System.out Scanner in = new Scanner(inputStream); in new Scanner(inputStream) PrintWriter out = new PrintWriter(outputStream); out new PrintWriter(outputStream) TaskB solver = new TaskB(); solver new TaskB() solver.solve(1, in, out) solver.solve solver 1 in out out.close() out.close out String[] args args static class TaskB {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            int n = in.nextInt();
            HashSet<Integer> a = new HashSet<Integer>();

            for (int i = 0; i < n; i++) {
                a.add(in.nextInt());
            }


            out.print(a.size());
        }

    } TaskB public void solve(int testNumber, Scanner in, PrintWriter out) {
            int n = in.nextInt();
            HashSet<Integer> a = new HashSet<Integer>();

            for (int i = 0; i < n; i++) {
                a.add(in.nextInt());
            }


            out.print(a.size());
        } solve {
            int n = in.nextInt();
            HashSet<Integer> a = new HashSet<Integer>();

            for (int i = 0; i < n; i++) {
                a.add(in.nextInt());
            }


            out.print(a.size());
        } int n = in.nextInt(); n in.nextInt() in.nextInt in HashSet<Integer> a = new HashSet<Integer>(); a new HashSet<Integer>() for (int i = 0; i < n; i++) {
                a.add(in.nextInt());
            } int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
                a.add(in.nextInt());
            } {
                a.add(in.nextInt());
            } a.add(in.nextInt()) a.add a in.nextInt() in.nextInt in out.print(a.size()) out.print out a.size() a.size a int testNumber testNumber Scanner in in PrintWriter out out public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TaskB solver = new TaskB();
        solver.solve(1, in, out);
        out.close();
    }

    static class TaskB {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            int n = in.nextInt();
            HashSet<Integer> a = new HashSet<Integer>();

            for (int i = 0; i < n; i++) {
                a.add(in.nextInt());
            }


            out.print(a.size());
        }

    }
} public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TaskB solver = new TaskB();
        solver.solve(1, in, out);
        out.close();
    }

    static class TaskB {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            int n = in.nextInt();
            HashSet<Integer> a = new HashSet<Integer>();

            for (int i = 0; i < n; i++) {
                a.add(in.nextInt());
            }


            out.print(a.size());
        }

    }
} Main
import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.HashSet;
import java.util.Scanner;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TaskB solver = new TaskB();
        solver.solve(1, in, out);
        out.close();
    }

    static class TaskB {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            int n = in.nextInt();
            HashSet<Integer> a = new HashSet<Integer>();

            for (int i = 0; i < n; i++) {
                a.add(in.nextInt());
            }


            out.print(a.size());
        }

    }
}

