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

[EX Q]: Sentence: 'seagulls sit on the posts of a seaside balcony by a clock tower'. Find frequency of the letter 'g'
[EX A]: 1

[EX Q]: Sentence: 'a desk covered in notepads, a laptop and other devices'. Find frequency of the letter 'c'
[EX A]: 2

[EX Q]: Sentence: 'a los angeles school bus parked in a parking lot'. Find frequency of the letter 'a'
[EX A]:
5