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: 'a bathroom sink and mirror with someone personal belongings on it'. How many words start with the letter 'p' in the sentence.
Example Output: 1

Example Input: Sentence: 'several white boats are anchored at a marina'. How many words start with the letter 's' in the sentence.
Example Output: 1

Example Input: Sentence: 'very many vehicles on the highway and also the motorbikes'. How many words start with the letter 'h' in the sentence.
Example Output:
1