1) any letters can change into an a
2) two c's in a row can turn into a b
3) any word can be doubled

now how can i change cac into caac while following those rules

also when you double you have to double all letters

CAC can be changed into CAAC. This is because the first rule says that any letter can change into an A so
 CAC=CAA
The last condition says that when you double , you have to double all letters,
Since A has been doubled,C needs to be doubled too.So:
CAA=CAAC

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