Given a non-empty string s consisting only of lowercase English letters, return the number of substrings in which the number of vowels equals the number of consonants. Vowels are the letters 'a', 'e', 'i', 'o', 'u'. A substring is a contiguous sequence of characters within s. The answer should count all substrings (including overlapping ones) that have equal counts of vowels and consonants.
('abae',)2