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

### Instruction:
 詹姆斯的键盘缺少了1/7的辅音和两个元音。总共缺少多少个键？


### Response:
 首先找出缺少的辅音数量：21个辅音 * 1/7 = 3个辅音
然后将缺少的元音数量加上去，得到总数：3个辅音 + 2个元音 = <<3+2=5>>5个键