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

[Q]: Sentence: 'a couple of men sitting next to each other under an umbrella'. Find frequency of the letter 'n'
[A]: 5


[Q]: Sentence: 'a bird is perched on a container in a person's hand'. Find frequency of the letter 'c'
[A]: 2


[Q]: Sentence: 'many people are flying kites on a beach'. Find frequency of the letter 'n'
[A]:
3