import java.util.Arrays;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int N = sc.nextInt();
        int[] d = new int[N];
        for (int i = 0; i < d.length; ++i) {
            d[i] = sc.nextInt();
        }

        System.out.println(solve(d));

        sc.close();
    }

    static int solve(int[] d) {
        return (int) Arrays.stream(d).distinct().count();
    }
} import java.util.Arrays; Arrays java.util import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int N = sc.nextInt();
        int[] d = new int[N];
        for (int i = 0; i < d.length; ++i) {
            d[i] = sc.nextInt();
        }

        System.out.println(solve(d));

        sc.close();
    }

    static int solve(int[] d) {
        return (int) Arrays.stream(d).distinct().count();
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int N = sc.nextInt();
        int[] d = new int[N];
        for (int i = 0; i < d.length; ++i) {
            d[i] = sc.nextInt();
        }

        System.out.println(solve(d));

        sc.close();
    } main {
        Scanner sc = new Scanner(System.in);

        int N = sc.nextInt();
        int[] d = new int[N];
        for (int i = 0; i < d.length; ++i) {
            d[i] = sc.nextInt();
        }

        System.out.println(solve(d));

        sc.close();
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int N = sc.nextInt(); N sc.nextInt() sc.nextInt sc int[] d = new int[N]; d new int[N] N for (int i = 0; i < d.length; ++i) {
            d[i] = sc.nextInt();
        } int i = 0; int i = 0; i 0 i < d.length i d.length d d.length ++i ++i i {
            d[i] = sc.nextInt();
        } {
            d[i] = sc.nextInt();
        } d[i] = sc.nextInt() d[i] d i sc.nextInt() sc.nextInt sc System.out.println(solve(d)) System.out.println System.out System System.out solve(d) solve d sc.close() sc.close sc String[] args args static int solve(int[] d) {
        return (int) Arrays.stream(d).distinct().count();
    } solve {
        return (int) Arrays.stream(d).distinct().count();
    } return (int) Arrays.stream(d).distinct().count(); (int) Arrays.stream(d).distinct().count() Arrays.stream(d).distinct().count Arrays.stream(d).distinct() Arrays.stream(d).distinct Arrays.stream(d) Arrays.stream Arrays d int[] d d public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int N = sc.nextInt();
        int[] d = new int[N];
        for (int i = 0; i < d.length; ++i) {
            d[i] = sc.nextInt();
        }

        System.out.println(solve(d));

        sc.close();
    }

    static int solve(int[] d) {
        return (int) Arrays.stream(d).distinct().count();
    }
} public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int N = sc.nextInt();
        int[] d = new int[N];
        for (int i = 0; i < d.length; ++i) {
            d[i] = sc.nextInt();
        }

        System.out.println(solve(d));

        sc.close();
    }

    static int solve(int[] d) {
        return (int) Arrays.stream(d).distinct().count();
    }
} Main
import java.util.Arrays;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int N = sc.nextInt();
        int[] d = new int[N];
        for (int i = 0; i < d.length; ++i) {
            d[i] = sc.nextInt();
        }

        System.out.println(solve(d));

        sc.close();
    }

    static int solve(int[] d) {
        return (int) Arrays.stream(d).distinct().count();
    }
}