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

### Instruction:
Bella bought stamps at the post office. Some of the stamps had a snowflake design, some had a truck design, and some had a rose design. Bella bought 11 snowflake stamps. She bought 9 more truck stamps than snowflake stamps, and 13 fewer rose stamps than truck stamps. How many stamps did Bella buy in all?

### Response:
 Idadi ya stempu za lori ni 11 + 9 = <<11+9=20>>20.
Idadi ya stempu za ua ni 20 - 13 = <<20-13=7>>7.
Bella alinunua jumla ya stempu 11 + 20 + 7 = <<11+20+7=38>>38.