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

[EX Q]: Sentence: 'two people under an umbrella while walking down a sidewalk'. Find frequency of the letter 'i'
[EX A]: 3

[EX Q]: Sentence: 'a very big nice looking living room with nice furnishings'. Find frequency of the letter 'e'
[EX A]: 3

[EX Q]: Sentence: 'the train is on the track and under a bridge'. Find frequency of the letter 'r'
[EX A]:
4