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 man about to take a swing at a tennis ball'. Count the number of vowels in the given sentence.
Example Output: 15

Example Input: Sentence: 'groups of people in a field sitting down, standing and walking, with tent areas in the background'. Count the number of vowels in the given sentence.
Example Output: 28

Example Input: Sentence: 'a dog lying on its back on a bed'. Count the number of consonants in the given sentence.
Example Output:
15