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.

Input: Consider Input: Sentence: 'the zebra is walking through the tall brown grass'. How many words start with the letter 't' in the sentence.

Output: 4

Input: Consider Input: Sentence: 'a cat inside a window looking out near another cat'. How many words start with the letter 'n' in the sentence.

Output: 1

Input: Consider Input: Sentence: 'a person eating a donut while a cat watches'. How many words start with the letter 'w' in the sentence.
Output: 2