Use the following information for the next two questions:

$3.$ A credit default swap requires a semiannual payment at the rate of $75$ basis points per year. The principal is $$450$ million and the credit default swap is settled in cash. A default occurs after three years and one months, and the calculation agent estimates that the price of the cheapest deliverable bond is $35\%$ of its face value shortly after the default. What is the amount of the semiannual payment to the seller of the credit default swap?

$4.$ How much does the seller of the credit default swap have to pay at the time of the default?