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: 'dog playing frisbee on the beach with ocean in background'. How many words start with the letter 'o' in the sentence.
Example Output: 2

Example Input: Sentence: 'a traffic light with a red light and an arrow pointing to the right'. How many words start with the letter 't' in the sentence.
Example Output: 3

Example Input: Sentence: 'a woman is posing on a floor with a stuffed toy'. How many words start with the letter 'i' in the sentence.
Example Output:
1