import java.util.*;
import java.lang.*;

public class Main {
    public static void main(String[] args) {
        Scanner dataScanner = new Scanner(System.in);
        int numLayers = Integer.parseInt(dataScanner.nextLine());
        HashSet<Integer> diameter = new HashSet<Integer>();
        for (int i = 0; i < numLayers; i++) {
            diameter.add(Integer.parseInt(dataScanner.nextLine()));
        }
        System.out.println(diameter.size());
    }
} import java.util.*; util.* java import java.lang.*; lang.* java public class Main {
    public static void main(String[] args) {
        Scanner dataScanner = new Scanner(System.in);
        int numLayers = Integer.parseInt(dataScanner.nextLine());
        HashSet<Integer> diameter = new HashSet<Integer>();
        for (int i = 0; i < numLayers; i++) {
            diameter.add(Integer.parseInt(dataScanner.nextLine()));
        }
        System.out.println(diameter.size());
    }
} Main public static void main(String[] args) {
        Scanner dataScanner = new Scanner(System.in);
        int numLayers = Integer.parseInt(dataScanner.nextLine());
        HashSet<Integer> diameter = new HashSet<Integer>();
        for (int i = 0; i < numLayers; i++) {
            diameter.add(Integer.parseInt(dataScanner.nextLine()));
        }
        System.out.println(diameter.size());
    } main {
        Scanner dataScanner = new Scanner(System.in);
        int numLayers = Integer.parseInt(dataScanner.nextLine());
        HashSet<Integer> diameter = new HashSet<Integer>();
        for (int i = 0; i < numLayers; i++) {
            diameter.add(Integer.parseInt(dataScanner.nextLine()));
        }
        System.out.println(diameter.size());
    } Scanner dataScanner = new Scanner(System.in); dataScanner new Scanner(System.in) int numLayers = Integer.parseInt(dataScanner.nextLine()); numLayers Integer.parseInt(dataScanner.nextLine()) Integer.parseInt Integer dataScanner.nextLine() dataScanner.nextLine dataScanner HashSet<Integer> diameter = new HashSet<Integer>(); diameter new HashSet<Integer>() for (int i = 0; i < numLayers; i++) {
            diameter.add(Integer.parseInt(dataScanner.nextLine()));
        } int i = 0; int i = 0; i 0 i < numLayers i numLayers i++ i++ i {
            diameter.add(Integer.parseInt(dataScanner.nextLine()));
        } {
            diameter.add(Integer.parseInt(dataScanner.nextLine()));
        } diameter.add(Integer.parseInt(dataScanner.nextLine())) diameter.add diameter Integer.parseInt(dataScanner.nextLine()) Integer.parseInt Integer dataScanner.nextLine() dataScanner.nextLine dataScanner System.out.println(diameter.size()) System.out.println System.out System System.out diameter.size() diameter.size diameter String[] args args public class Main {
    public static void main(String[] args) {
        Scanner dataScanner = new Scanner(System.in);
        int numLayers = Integer.parseInt(dataScanner.nextLine());
        HashSet<Integer> diameter = new HashSet<Integer>();
        for (int i = 0; i < numLayers; i++) {
            diameter.add(Integer.parseInt(dataScanner.nextLine()));
        }
        System.out.println(diameter.size());
    }
} public class Main {
    public static void main(String[] args) {
        Scanner dataScanner = new Scanner(System.in);
        int numLayers = Integer.parseInt(dataScanner.nextLine());
        HashSet<Integer> diameter = new HashSet<Integer>();
        for (int i = 0; i < numLayers; i++) {
            diameter.add(Integer.parseInt(dataScanner.nextLine()));
        }
        System.out.println(diameter.size());
    }
} Main
import java.util.*;
import java.lang.*;

public class Main {
    public static void main(String[] args) {
        Scanner dataScanner = new Scanner(System.in);
        int numLayers = Integer.parseInt(dataScanner.nextLine());
        HashSet<Integer> diameter = new HashSet<Integer>();
        for (int i = 0; i < numLayers; i++) {
            diameter.add(Integer.parseInt(dataScanner.nextLine()));
        }
        System.out.println(diameter.size());
    }
}
