def separate_categories(invoice_lines: dict):
    """
    This function separates categories and counts their prices. Decimal euros are converted into integer cents.

    :param invoice_lines: dictionary with invoice lines
    :return: dictionary with separated categories
    """

    categories = {}

    for invoice in invoice_lines:
        price = int(invoice['unit_price_net'].replace('.', '')) * invoice['quantity']

        if invoice['category'] in categories:
            categories[invoice['category']] += price
        else:
            categories[invoice['category']] = price

    return categories