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

### Instruction:
Jerry paid off some of his debts. Two months ago, he paid $12 while last month, he paid $3 more. If his debt was $50 in all, how much does he still have to pay?

### Response:
 เจอร์รี่จ่าย $12 + $3 = $<<12+3=15>>15.
ดังนั้น เขาต้องจ่ายเงินเพิ่มอีก $50 - $15 = $<<50-15=35>>35.