In this task, you need to count the number of times the given letter appears in the given sentence.

Ex Input:
Sentence: 'different sets of luggage in a baggage claim area'. Find frequency of the letter 'r'

Ex Output:
2


Ex Input:
Sentence: 'a closeup view of a bathroom sink, that is very modern'. Find frequency of the letter 'e'

Ex Output:
4


Ex Input:
Sentence: 'a body of water with hoses of either side'. Find frequency of the letter 'w'

Ex Output:

2