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

/**
 * 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);
        ABC085B solver = new ABC085B();
        solver.solve(1, in, out);
        out.close();
    }

    static class ABC085B {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            // 整数の入力
            int n = Integer.parseInt(in.next());
            Integer[] d = new Integer[n];
            for (int i = 0; i < n; i++) {
                d[i] = Integer.parseInt(in.next());
            }
            Set<Integer> ans = new HashSet();
            for (int i = 0; i < n; i++) {
                ans.add(d[i]);
            }


            // 出力
            out.println(ans.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 import java.util.Set; Set 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);
        ABC085B solver = new ABC085B();
        solver.solve(1, in, out);
        out.close();
    }

    static class ABC085B {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            // 整数の入力
            int n = Integer.parseInt(in.next());
            Integer[] d = new Integer[n];
            for (int i = 0; i < n; i++) {
                d[i] = Integer.parseInt(in.next());
            }
            Set<Integer> ans = new HashSet();
            for (int i = 0; i < n; i++) {
                ans.add(d[i]);
            }


            // 出力
            out.println(ans.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);
        ABC085B solver = new ABC085B();
        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);
        ABC085B solver = new ABC085B();
        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) ABC085B solver = new ABC085B(); solver new ABC085B() solver.solve(1, in, out) solver.solve solver 1 in out out.close() out.close out String[] args args static class ABC085B {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            // 整数の入力
            int n = Integer.parseInt(in.next());
            Integer[] d = new Integer[n];
            for (int i = 0; i < n; i++) {
                d[i] = Integer.parseInt(in.next());
            }
            Set<Integer> ans = new HashSet();
            for (int i = 0; i < n; i++) {
                ans.add(d[i]);
            }


            // 出力
            out.println(ans.size());

        }

    } ABC085B public void solve(int testNumber, Scanner in, PrintWriter out) {
            // 整数の入力
            int n = Integer.parseInt(in.next());
            Integer[] d = new Integer[n];
            for (int i = 0; i < n; i++) {
                d[i] = Integer.parseInt(in.next());
            }
            Set<Integer> ans = new HashSet();
            for (int i = 0; i < n; i++) {
                ans.add(d[i]);
            }


            // 出力
            out.println(ans.size());

        } solve {
            // 整数の入力
            int n = Integer.parseInt(in.next());
            Integer[] d = new Integer[n];
            for (int i = 0; i < n; i++) {
                d[i] = Integer.parseInt(in.next());
            }
            Set<Integer> ans = new HashSet();
            for (int i = 0; i < n; i++) {
                ans.add(d[i]);
            }


            // 出力
            out.println(ans.size());

        } int n = Integer.parseInt(in.next()); n Integer.parseInt(in.next()) Integer.parseInt Integer in.next() in.next in Integer[] d = new Integer[n]; d new Integer[n] n for (int i = 0; i < n; i++) {
                d[i] = Integer.parseInt(in.next());
            } int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
                d[i] = Integer.parseInt(in.next());
            } {
                d[i] = Integer.parseInt(in.next());
            } d[i] = Integer.parseInt(in.next()) d[i] d i Integer.parseInt(in.next()) Integer.parseInt Integer in.next() in.next in Set<Integer> ans = new HashSet(); ans new HashSet() for (int i = 0; i < n; i++) {
                ans.add(d[i]);
            } int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
                ans.add(d[i]);
            } {
                ans.add(d[i]);
            } ans.add(d[i]) ans.add ans d[i] d i out.println(ans.size()) out.println out ans.size() ans.size ans 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);
        ABC085B solver = new ABC085B();
        solver.solve(1, in, out);
        out.close();
    }

    static class ABC085B {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            // 整数の入力
            int n = Integer.parseInt(in.next());
            Integer[] d = new Integer[n];
            for (int i = 0; i < n; i++) {
                d[i] = Integer.parseInt(in.next());
            }
            Set<Integer> ans = new HashSet();
            for (int i = 0; i < n; i++) {
                ans.add(d[i]);
            }


            // 出力
            out.println(ans.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);
        ABC085B solver = new ABC085B();
        solver.solve(1, in, out);
        out.close();
    }

    static class ABC085B {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            // 整数の入力
            int n = Integer.parseInt(in.next());
            Integer[] d = new Integer[n];
            for (int i = 0; i < n; i++) {
                d[i] = Integer.parseInt(in.next());
            }
            Set<Integer> ans = new HashSet();
            for (int i = 0; i < n; i++) {
                ans.add(d[i]);
            }


            // 出力
            out.println(ans.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;
import java.util.Set;

/**
 * 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);
        ABC085B solver = new ABC085B();
        solver.solve(1, in, out);
        out.close();
    }

    static class ABC085B {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            // 整数の入力
            int n = Integer.parseInt(in.next());
            Integer[] d = new Integer[n];
            for (int i = 0; i < n; i++) {
                d[i] = Integer.parseInt(in.next());
            }
            Set<Integer> ans = new HashSet();
            for (int i = 0; i < n; i++) {
                ans.add(d[i]);
            }


            // 出力
            out.println(ans.size());

        }

    }
}

