def get_item_charge(amount_of_items: int) -> float:
    """
    This function calculates extra item fee  and adds it to delivery fee.
    ---

    Args: 
        amount_of_items (int): amount of items in the basket

    Returns: 
        item_charge (float): fee for extra items
    """
    item_limit = 5
    free_items = 4
    extra_item_charge = 50
    if amount_of_items >= item_limit:
        extra_items = amount_of_items - free_items
        return extra_item_charge * extra_items
    return 0