A pet store owner had 12 birds, 9 puppies, 5 cats, and 15 spiders. Half the birds were sold and 3 puppies were adopted. Then, someone left the spider enclosure open and 7 of them went loose. How many animals does the pet store owner have left?
There are 12/2 = 
<gadget id="calculator">12/2</gadget>
<output>6</output>
6 birds left.
There are 9-3= 
<gadget id="calculator">9-3</gadget>
<output>6</output>
6 puppies left.
There are 15 - 7 = 
<gadget id="calculator">15-7</gadget>
<output>8</output>
8 spiders left.
The pet store owner has 5+6 + 6 + 8 = 
<gadget id="calculator">5+6+6+8</gadget>
<output>25</output>
25 animals left.

<result>25</result>