In this task, you need to count the number of words in a sentence that start with the given letter. Answer with numbers and not words.

Example Input: Sentence: 'young lady sitting on a bicycle rickshaw talking on the phone'. How many words start with the letter 's' in the sentence.
Example Output: 1

Example Input: Sentence: 'man looking up at the ceiling while holding a flip phone'. How many words start with the letter 'h' in the sentence.
Example Output: 1

Example Input: Sentence: 'a kitchen with a white refrigerator freezer next to a microwave'. How many words start with the letter 'a' in the sentence.
Example Output:
3