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?
Jonathan has 8 +10 = 
<gadget id="calculator">8+10</gadget>
<output>18</output>
18 letters in his name.
His sister has 5+10 = 
<gadget id="calculator">5+10</gadget>
<output>15</output>
15 letters in her name.
The total number of letters in their names is 18+15 = 
<gadget id="calculator">18+15</gadget>
<output>33</output>
33.

<result>33</result>