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

[EX Q]: Sentence: 'a bunch of green bananas is hanging on a tree'. Find frequency of the letter 'n'
[EX A]: 7

[EX Q]: Sentence: 'a flock of sheep grazing in a park'. Find frequency of the letter 'f'
[EX A]: 2

[EX Q]: Sentence: 'in front of a blurred back area with foot traffic, an older man with glasses, cap, and apron, is working a machine with a turning wheel on it'. Find frequency of the letter 'a'
[EX A]:
14