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

[EX Q]: Sentence: 'a little boy standing near a couch and a table'. Find frequency of the letter 'i'
[EX A]: 2

[EX Q]: Sentence: 'bathroom scene with a black cat going behind the door'. Find frequency of the letter 'e'
[EX A]: 4

[EX Q]: Sentence: 'two sheep are standing on a grassy field'. Find frequency of the letter 'o'
[EX A]:
2