import java.util.HashSet;
import java.util.Scanner;
import java.util.Set;

public class Main {
    public static void main(String[] args) {
        Scanner cin = new Scanner(System.in);
        int N = cin.nextInt();
        int[] d = new int[N];
        for (int i = 0; i < N; i++) {
            d[i] = cin.nextInt();
        }

        Set<Integer> s = new HashSet<>();
        for (int i = 0; i < N; i++) {
            s.add(d[i]);
        }

        System.out.println(s.size());
    }
} 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) {
        Scanner cin = new Scanner(System.in);
        int N = cin.nextInt();
        int[] d = new int[N];
        for (int i = 0; i < N; i++) {
            d[i] = cin.nextInt();
        }

        Set<Integer> s = new HashSet<>();
        for (int i = 0; i < N; i++) {
            s.add(d[i]);
        }

        System.out.println(s.size());
    }
} Main public static void main(String[] args) {
        Scanner cin = new Scanner(System.in);
        int N = cin.nextInt();
        int[] d = new int[N];
        for (int i = 0; i < N; i++) {
            d[i] = cin.nextInt();
        }

        Set<Integer> s = new HashSet<>();
        for (int i = 0; i < N; i++) {
            s.add(d[i]);
        }

        System.out.println(s.size());
    } main {
        Scanner cin = new Scanner(System.in);
        int N = cin.nextInt();
        int[] d = new int[N];
        for (int i = 0; i < N; i++) {
            d[i] = cin.nextInt();
        }

        Set<Integer> s = new HashSet<>();
        for (int i = 0; i < N; i++) {
            s.add(d[i]);
        }

        System.out.println(s.size());
    } Scanner cin = new Scanner(System.in); cin new Scanner(System.in) int N = cin.nextInt(); N cin.nextInt() cin.nextInt cin int[] d = new int[N]; d new int[N] N for (int i = 0; i < N; i++) {
            d[i] = cin.nextInt();
        } int i = 0; int i = 0; i 0 i < N i N i++ i++ i {
            d[i] = cin.nextInt();
        } {
            d[i] = cin.nextInt();
        } d[i] = cin.nextInt() d[i] d i cin.nextInt() cin.nextInt cin Set<Integer> s = new HashSet<>(); s new HashSet<>() for (int i = 0; i < N; i++) {
            s.add(d[i]);
        } int i = 0; int i = 0; i 0 i < N i N i++ i++ i {
            s.add(d[i]);
        } {
            s.add(d[i]);
        } s.add(d[i]) s.add s d[i] d i System.out.println(s.size()) System.out.println System.out System System.out s.size() s.size s String[] args args public class Main {
    public static void main(String[] args) {
        Scanner cin = new Scanner(System.in);
        int N = cin.nextInt();
        int[] d = new int[N];
        for (int i = 0; i < N; i++) {
            d[i] = cin.nextInt();
        }

        Set<Integer> s = new HashSet<>();
        for (int i = 0; i < N; i++) {
            s.add(d[i]);
        }

        System.out.println(s.size());
    }
} public class Main {
    public static void main(String[] args) {
        Scanner cin = new Scanner(System.in);
        int N = cin.nextInt();
        int[] d = new int[N];
        for (int i = 0; i < N; i++) {
            d[i] = cin.nextInt();
        }

        Set<Integer> s = new HashSet<>();
        for (int i = 0; i < N; i++) {
            s.add(d[i]);
        }

        System.out.println(s.size());
    }
} Main
import java.util.HashSet;
import java.util.Scanner;
import java.util.Set;

public class Main {
    public static void main(String[] args) {
        Scanner cin = new Scanner(System.in);
        int N = cin.nextInt();
        int[] d = new int[N];
        for (int i = 0; i < N; i++) {
            d[i] = cin.nextInt();
        }

        Set<Integer> s = new HashSet<>();
        for (int i = 0; i < N; i++) {
            s.add(d[i]);
        }

        System.out.println(s.size());
    }
}
