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

[EX Q]: Sentence: 'a girl laying on a bed posing for a picture'. Find frequency of the letter 'i'
[EX A]: 4

[EX Q]: Sentence: 'a small white dog looking out a car window'. Find frequency of the letter 'l'
[EX A]: 3

[EX Q]: Sentence: 'an animal that is licking the neck of another animal'. Find frequency of the letter 'e'
[EX A]:
3