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

### Instruction:
There are 21 cherry tomatoes on the tomato plant.  2 birds eat one-third of the tomatoes.  How many are still left on the tomato plant?

### Response:
 นกกินลูกมะเขือเทศจำนวนนี้: 21 / 3 = <<21/3=7>>7 ลูก
มีลูกมะเขือเทศที่เหลืออยู่บนต้น: 21 - 7 = <<21-7=14>>14 ลูก