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

Example Input: Sentence: 'There is a silver and blue fire hydrant on a grass field'. Count the number of nouns in this sentence.
Example Output: 5

Example Input: Sentence: 'A person is walking with their dog in a backpack in the park'. Count the number of nouns in this sentence.
Example Output: 4

Example Input: Sentence: 'Two zebras are both eating grass at the same time'. Count the number of verbs in this sentence.
Example Output:
1