In this task, you need to count the number of words in a sentence that contain the given letter

Ex Input:
Sentence: 'a white plate of food including rice and vegetables with beef'. How many words contain the letter 'o' in the sentence.

Ex Output:
2


Ex Input:
Sentence: 'young girls with backpacks are standing near stairs that look to go to the subway'. How many words contain the letter 'r' in the sentence.

Ex Output:
4


Ex Input:
Sentence: 'a young man standing at the bottom of a ski hill'. How many words contain the letter 'e' in the sentence.

Ex Output:

1