In this task, you need to count the number of vowels (letters 'a', 'e', 'i', 'o', 'u') / consonants (all letters other than vowels) in the given sentence.

Example Input: Sentence: 'a black bear standing on the ground with grass'. Count the number of vowels in the given sentence.
Example Output: 12

Example Input: Sentence: 'a sign on a lamp post indicates yellow brick road'. Count the number of consonants in the given sentence.
Example Output: 25

Example Input: Sentence: 'an owl sitting on a branch in a forest'. Count the number of consonants in the given sentence.
Example Output:
19