In this task, you need to count the number of nouns/verbs in the given sentence.

Example Input: Sentence: 'A tennis player is trying to hit the ball'. Count the number of nouns in this sentence.
Example Output: 3

Example Input: Sentence: 'Two young girls sitting on top of a bench'. Count the number of nouns in this sentence.
Example Output: 3

Example Input: Sentence: 'a flock of birds flying outside at sunset'. Count the number of nouns in this sentence.
Example Output:
3