In magic school, Wizard James, who feeds many animals, can turn his frogs into dragonflies and dragonflies into frogs. At first, he counts that the amount of frogs is $$9$$ more than that of dragonflies. After he finishes the magic show, there are $$11$$ frogs and $$10$$ dragonflies in total. How many frogs did he have at the beginning? 
Overseas Competition->Knowledge Point->Word Problem Modules->Questions Involving Sum, Difference and Multiples->Problems Involving Sum and Difference