If there is no vowel in the subsequence yet , add vowel at current index if it is ' a ' , else move on to the next character in the string
if len ( subList ) == 0 : NEW_LINE INDENT if string [ index ] != ' a ' : NEW_LINE INDENT return longestSubsequence ( string , subList , index + 1 ) NEW_LINE DEDENT else : NEW_LINE INDENT return longestSubsequence ( string , subList +   \ [ string [ index ] ] , index + 1 ) NEW_LINE DEDENT DEDENT