How to implement dynamic form in symfony?

Question

symfony

Good afternoon.
We need to implement the following thing. There is the essence of the competition and there is the essence of prizes, for each competition there can be several prizes, depending on how many winners there will be in the competition.
And we need such a form, the user enters a number of winners into the input, let's say 5, then we need to display 5 inputs, where he will enter the names of the prizes.
How to make such a form correctly and how then to get this data and write it to the database?
The essence of the competition

/**
 * @ORM\Entity
 * @ORM\Table(name="contest")
 */
class Contest
{
/**
     * @ORM\Id
     * @ORM\Column(type="integer")
     * @ORM\GeneratedValue(strategy="AUTO")
     */
    protected $id;

    /**
     * @ORM\Column(type="string")
     * @Assert\NotBlank()
     */
    protected $name;

     /**
     * @ORM\OneToMany(targetEntity="Prize", mappedBy="contest")
     * @ORM\OrderBy({"place" = "ASC"})
     */
    protected $prizes;
}

Essence of prizes

/**
 * @ORM\Entity
 * @ORM\Table(name="prize")
 */
class Prize
{
    /**
     * @ORM\Id
     * @ORM\Column(type="integer")
     * @ORM\GeneratedValue(strategy="AUTO")
     */
    protected $id;

    /**
     * @ORM\ManyToOne(targetEntity="Contest", inversedBy="prizes")
     * @ORM\JoinColumn(name="contest_id", referencedColumnName="id")
     */
    protected $contest;

    /**
     * @ORM\Column(type="integer")
     */
    protected $place;

    /**
     * @ORM\Column(type="string")
     */
    protected $name;
}

Answer 1

Through collections and prototypes. The user himself will be able to add as many inputs for prizes as he wants