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

### Instruction:
Mary was working on a research paper and already had borrowed 5 books from the library.  3 books weren't helpful so she returned those and checked out 5 more books.  3 days later, she went back to the library and returned 2 of those books and checked out 7 more books.  How many books does Mary currently have checked out of the library?

### Response:
 Mary alianza na vitabu 5 na akavirudisha 3 hivyo alikuwa na vitabu 5-3 = <<5-3=2>>2
Alikuwa na vitabu 2 na akakopa vitabu 5 zaidi hivyo alikuwa na vitabu 2+5 = <<2+5=7>>7
Sasa ana vitabu 7 lakini akarudisha 2 hivyo ana vitabu 7-2 = <<7-2=5>>5
Ana vitabu 5 na akakopa vitabu 7 zaidi hivyo ana vitabu 5+7 = <<5+7=12>>12 kutoka maktabani kwa sasa