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

### Instruction:
Jonathan's full name contains 8 letters for the first name and 10 letters for the surname. His sister's name has 5 letters for the first name and 10 letters for the second name. What's the total number of letters in their names?

### Response:
 Jonathan ana herufi 8+10 = <<8+10=18>>18 katika jina lake.
Dada yake ana herufi 5+10 = <<5+10=15>>15 katika jina lake.
Jumla ya herufi katika majina yao ni 18+15 = <<18+15=33>>33