import java.util.Scanner;
import java.util.Set;
import java.util.TreeSet;
import java.util.Arrays;

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

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

        Set<Integer> setD = new TreeSet<>(Arrays.asList(d));

        System.out.println(setD.size());
        sc.close();
    }
} import java.util.Scanner; Scanner java.util import java.util.Set; Set java.util import java.util.TreeSet; TreeSet java.util import java.util.Arrays; Arrays java.util public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();

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

        Set<Integer> setD = new TreeSet<>(Arrays.asList(d));

        System.out.println(setD.size());
        sc.close();
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();

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

        Set<Integer> setD = new TreeSet<>(Arrays.asList(d));

        System.out.println(setD.size());
        sc.close();
    } main {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();

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

        Set<Integer> setD = new TreeSet<>(Arrays.asList(d));

        System.out.println(setD.size());
        sc.close();
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int n = sc.nextInt(); n sc.nextInt() sc.nextInt sc Integer[] d = new Integer[n]; d new Integer[n] n for(int i=0; i<n; i++) {
            d[i] = sc.nextInt();
        } int i=0; int i=0; i 0 i<n i n i++ i++ i {
            d[i] = sc.nextInt();
        } {
            d[i] = sc.nextInt();
        } d[i] = sc.nextInt() d[i] d i sc.nextInt() sc.nextInt sc Set<Integer> setD = new TreeSet<>(Arrays.asList(d)); setD new TreeSet<>(Arrays.asList(d)) System.out.println(setD.size()) System.out.println System.out System System.out setD.size() setD.size setD sc.close() sc.close sc String[] args args public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();

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

        Set<Integer> setD = new TreeSet<>(Arrays.asList(d));

        System.out.println(setD.size());
        sc.close();
    }
} public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();

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

        Set<Integer> setD = new TreeSet<>(Arrays.asList(d));

        System.out.println(setD.size());
        sc.close();
    }
} Main
import java.util.Scanner;
import java.util.Set;
import java.util.TreeSet;
import java.util.Arrays;

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

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

        Set<Integer> setD = new TreeSet<>(Arrays.asList(d));

        System.out.println(setD.size());
        sc.close();
    }
}
