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

[EX Q]: Sentence: 'a guy riding a bike close to a car in the street'. Find frequency of the letter 'i'
[EX A]: 4

[EX Q]: Sentence: 'a group of cows that are standing in the grass'. Find frequency of the letter 'g'
[EX A]: 3

[EX Q]: Sentence: 'a white bathroom with a carefully gift-wrapped toilet bowl'. Find frequency of the letter 'l'
[EX A]:
4