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

Ex Input:
Sentence: 'trash cans and a fire hydrant are on the curb of a sidewalk'. How many words contain the letter 'u' in the sentence.

Ex Output:
1


Ex Input:
Sentence: 'a white biplane on grassy area next to buildings'. How many words contain the letter 'g' in the sentence.

Ex Output:
2


Ex Input:
Sentence: 'line of pedestrians walking in the rain with umbrellas beside a river'. How many words contain the letter 'e' in the sentence.

Ex Output:

6