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

### Instruction:
 南希有六双靴子，比靴子多九双拖鞋，以及与拖鞋和靴子总数的三倍相等的高跟鞋双数。她有多少双鞋子（单鞋，不是双鞋）？


### Response:
 首先找出南希拥有的拖鞋双数：6双 + 9双 = <<6+9=15>>15双
然后将该数字加上她拥有的靴子双数：15双 + 6双 = <<15+6=21>>21双
然后将该数字乘以三，找出她拥有的高跟鞋双数：21双 * 3 = <<21*3=63>>63双
然后将每种鞋子的双数相加：15双 + 6双 + 63双 = <<15+6+63=84>>84双
然后将该数字乘以2（因为每双鞋由两只单鞋组成），找出她拥有的鞋子总数：84双 * 2鞋/双 = <<84*2=168>>168鞋