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 hot dog in a bun with ketchup on a plate with french fries'. How many words start with the letter 'a' in the sentence.
Example output: 3
Example explanation: The word 'a' is the only word that starts with 'a'. This sentence has 3 occurrences of the word 'a'. So, the answer is 3.
Q: Sentence: 'a long rectangular gourmet pizza on a metal tray'. How many words start with the letter 'l' in the sentence.
A:
1