Applying for additional shares

Hi sorry for the dumb question as Im a little confused I want to apply for additional shares in the raising from the offer booklet:
The allocation policy is that each eligible shareholder that takes up their offer in full will be allocated additional new shares for which the eligible shareholder subscribes under the top up facility that is the lesser of:
a) the number (if any) of additional new shares subscribed for under the top up facility and
b) the greater of (i) $5000 of additional new shares (1471 additional new shares at the issue price of $3.40) and (ii) 20% of the shareholders entitlement

As an example if Im allocated 500 new shares in the entitlement how many extra shares can I apply for (minimum and maximum) So If I pay with bpay I just add the total amount and pay in one go thanks in advance