Basically enough. Remember, as soon as you exit the border, go to the nearest subway station and buy an Octopus card (the card can be recharged at any 7-11 store and used to pay for purchases) and get a free map guide. It is best to use a credit card or debit card for consumption. Remember to ask the store or cashier to use UnionPay to settle the bill. Don't be tempted to use VISA or MasterCard to settle the bill. Otherwise, you will have to repay in U.S. dollars when you return to China...and try your best to do so. Do not use Hong Kong ATM cash machines for overseas transfers, as the handling fees will not be worth it~