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

[EX Q]: Sentence: 'a man sitting on a motorcycle near two other men'. Find frequency of the letter 'r'
[EX A]: 3

[EX Q]: Sentence: 'a young girl is brushing her teeth in this dated photo'. Find frequency of the letter 't'
[EX A]: 5

[EX Q]: Sentence: 'a street sign is in the middle of a cemetery,'. Find frequency of the letter 'e'
[EX A]:
7