Below is an instruction that describes a task. Write a response that appropriately completes the request in Thai. Please answer in Thai.

### Instruction:
Last week, Charles bought a t-shirt for $30, a backpack for $10, and a blue cap for $5. The store gave him a discount and, in total, he only spent $43. How much of a discount did they give him, in dollars?

### Response:
 ชาร์ลส์เสียเงิน $30 + $10 + $5 = <<30+10+5=45>>$45 สำหรับสิ่งที่เขาซื้อ
ส่วนลดคือ $45 - $43 = <<45-43=2>>$2.