import java.util.*;

public class KuponUndian {
    public static void main(String[] args) {
        HashSet<Integer> kupon = new HashSet<>();
        int[] masukan = {30, 7, 19, 3, 11};
        for (int n : masukan) {
            kupon.add(n);
        }
        System.out.println("Isi kupon : " + kupon);
        System.out.println("Ukuran    : " + kupon.size());

        System.out.println("contains(7)  : " + kupon.contains(7));
        System.out.println("contains(99) : " + kupon.contains(99));

        kupon.remove(7);
        System.out.println("Setelah remove(7): " + kupon);

        System.out.print("Iterasi   : ");
        for (int n : kupon) {
            System.out.print(n + " ");
        }
        System.out.println();
    }
}