Given the task definition, example input & output, solve the new input case.
In this task, you need to count the number of words in a sentence that contain the given letter
Example: Sentence: 'two gray birds standing in a green field'. How many words contain the letter 'a' in the sentence.
Output: 3
The words 'gray', 'standing', and 'a' contain the letter 'a'. So, the answer is 3.

New input case for you: Sentence: 'a man is walking by a place of business'. How many words contain the letter 'x' in the sentence.
Output:
0