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

Example Input: Sentence: 'There is a man walking towards the waves'. Count the number of nouns in this sentence.
Example Output: 2

Example Input: Sentence: 'Two cows stand next to each other in a field'. Count the number of nouns in this sentence.
Example Output: 2

Example Input: Sentence: 'Two men ski down the slope of a mountain'. Count the number of nouns in this sentence.
Example Output:
3