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

[EX Q]: Sentence: 'a woman throwing a frisbee on a field'. Find frequency of the letter 's'
[EX A]: 1

[EX Q]: Sentence: 'a double-decker bus covered in children's illustrations driving next to a van'. Find frequency of the letter 'a'
[EX A]: 4

[EX Q]: Sentence: 'a group of baby elephants walk next to an adult'. Find frequency of the letter 'a'
[EX A]:
6