What is the simplest way to count the total number of repeating sequential letters in a string? For example, if I have a string 'TCAAAAAAAACAT', I know I can count the total number of 'A's using the count function count(A). However, since I only want the number of 'As' that are sequential in the string (the ones in the middle), what would I do to have the script ignore any letters that are not repeating and sequential?