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 couple of computers are on top of a desk'. Count the number of consonants in the given sentence.
Example Output: 18

Example Input: Sentence: 'an old design kitchen with a long counter and brown appliances'. Count the number of vowels in the given sentence.
Example Output: 18

Example Input: Sentence: 'a man is carrying a bag and holding a skateboard'. Count the number of consonants in the given sentence.
Example Output:
24