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

[Q]: Sentence: 'a man serving himself pizza in a wooden booth'. Find frequency of the letter 'n'
[A]: 4


[Q]: Sentence: 'a few men walking through a market place'. Find frequency of the letter 'f'
[A]: 1


[Q]: Sentence: 'luggage waiting for pick up at baggage claim'. Find frequency of the letter 'a'
[A]:
6