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

[EX Q]: Sentence: 'a man and a woman are walking down the street with an umbrella over their heads'. Find frequency of the letter 'w'
[EX A]: 4

[EX Q]: Sentence: 'a young elephant is touching a bigger elephant with its trunk'. Find frequency of the letter 'i'
[EX A]: 5

[EX Q]: Sentence: 'cat laying in hammock made from a chair and blanket'. Find frequency of the letter 'i'
[EX A]:
3