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

### Instruction:
Nicky is trading baseball cards with Jill. If Nicky trades two cards worth $8 each for 1 card worth $21, how many dollars of profit does he make?

### Response:
First, add the cost of the two $8 cards: $8 + $8 = $<<8+8=16>>16
Then subtract the cost of the cards Nicky gave away from the cost of the card he received to find his profit: $21 - $16 = $<<21-16=5>>5
#### 5