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

### Instruction:
Diego baked 12 cakes for his sister's birthday. Donald also baked 4 cakes, but ate 1 while waiting for the party to start. How many cakes are left?

### Response:
 Diego alipopika keki 12, idadi ya jumla ya keki ilikuwa 12+4 = <<12+4=16>>16 keki.
Hata hivyo, Diego alikula keki 1, kwa hiyo kuna keki 16 - 1 = <<16-1=15>>15 zilizobaki.