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

### Instruction:
Joe's pizzeria has an amazing promotion. If you buy any regular large pizza you can get the next 3 medium pizzas for $5 each. What are your total savings if the regular medium pizza price is $18 and you take full advantage of the promotion?

### Response:
 Bei ya kawaida kwa pizza 4 za kati ingekuwa 18*4=$<<18*4=72>>72
Bei ya matangazo ni 18+5*3=$<<18+5*3=33>>33
Hivyo savings zako jumla ni 72-33=$<<72-33=39>>39