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 young man laying on top of a white toilet seat near a sink'. How many words start with the letter 'a' in the sentence.
Example Output: 3

Example Input: Sentence: 'a computer with a farm on the screen on top of a desk'. How many words start with the letter 'o' in the sentence.
Example Output: 3

Example Input: Sentence: 'a group of men standing in front of a display'. How many words start with the letter 'm' in the sentence.
Example Output:
1