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.

[EX Q]: Sentence: 'a clock tower atop a tall building with a lighting rod'. How many words start with the letter 'a' in the sentence.
[EX A]: 4

[EX Q]: Sentence: 'a person walking on a street with a umbrella'. How many words start with the letter 's' in the sentence.
[EX A]: 1

[EX Q]: Sentence: 'a guy squatting down and tapping his food with a woman sitting down'. How many words start with the letter 'f' in the sentence.
[EX A]:
1