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

### Instruction:
 爱丽丝正在她的院子周围种灌木。如果每边长度为16英尺，每棵灌木占据4英尺，她需要买多少棵灌木？


### Response:
 首先找出灌木需要覆盖的总距离：16英尺/边 * 3边 = <<16*3=48>>48英尺
然后将总距离除以每棵灌木占据的距离：48英尺 / 4英尺/灌木 = <<48/4=12>>12棵灌木