Hello I need a help in a weak mathematical induction

4. Given the alphabet A,B), suppose that you have the following rules for constructing words in a language L2: 1. Any single character from the alphabet is a word in language L2. 2. Other than single character words, every word in L2 is one of the following 1. A word in L2 ending in character A, followed by the character B 2. A word in L2 ending in character B, followed by the character A Prove by weak mathematical induction that language L2 does not contain any word with two successive A's e to search