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

[EX Q]: Sentence: 'a bus is stopped in front of a graphic statue'. Find frequency of the letter 'e'
[EX A]: 2

[EX Q]: Sentence: 'two zebra stand near the wooden posts on a building'. Find frequency of the letter 't'
[EX A]: 4

[EX Q]: Sentence: 'a large stone building with a clock on it'. Find frequency of the letter 'd'
[EX A]:
1