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 man holding up a smart phone with both hands'. How many words start with the letter 'm' in the sentence.
Example Output: 1

Example Input: Sentence: 'a flat screen tv with an image of a baseball player holding a baseball bat'. How many words start with the letter 'a' in the sentence.
Example Output: 4

Example Input: Sentence: 'a very big tasty looking dish with some rolls'. How many words start with the letter 'v' in the sentence.
Example Output:
1