import java.util.*;

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

        int N = Integer.parseInt(sc.next());

        Set<Integer> dSet = new HashSet<Integer>();

        for (int i=0; i<N; i++) {
            dSet.add(Integer.valueOf(sc.next()));
        }
        System.out.println(dSet.size());
    }
} import java.util.*; util.* java public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int N = Integer.parseInt(sc.next());

        Set<Integer> dSet = new HashSet<Integer>();

        for (int i=0; i<N; i++) {
            dSet.add(Integer.valueOf(sc.next()));
        }
        System.out.println(dSet.size());
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int N = Integer.parseInt(sc.next());

        Set<Integer> dSet = new HashSet<Integer>();

        for (int i=0; i<N; i++) {
            dSet.add(Integer.valueOf(sc.next()));
        }
        System.out.println(dSet.size());
    } main {
        Scanner sc = new Scanner(System.in);

        int N = Integer.parseInt(sc.next());

        Set<Integer> dSet = new HashSet<Integer>();

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

        int N = Integer.parseInt(sc.next());

        Set<Integer> dSet = new HashSet<Integer>();

        for (int i=0; i<N; i++) {
            dSet.add(Integer.valueOf(sc.next()));
        }
        System.out.println(dSet.size());
    }
} public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int N = Integer.parseInt(sc.next());

        Set<Integer> dSet = new HashSet<Integer>();

        for (int i=0; i<N; i++) {
            dSet.add(Integer.valueOf(sc.next()));
        }
        System.out.println(dSet.size());
    }
} Main
import java.util.*;

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

        int N = Integer.parseInt(sc.next());

        Set<Integer> dSet = new HashSet<Integer>();

        for (int i=0; i<N; i++) {
            dSet.add(Integer.valueOf(sc.next()));
        }
        System.out.println(dSet.size());
    }
}
