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

[EX Q]: Sentence: 'a baseball player dropping his bat and starting to run'. Find frequency of the letter 'o'
[EX A]: 2

[EX Q]: Sentence: 'a very big nice looking living room with nice furnishings'. Find frequency of the letter 'e'
[EX A]: 3

[EX Q]: Sentence: 'a man in black jacket and hat holding cds'. Find frequency of the letter 'i'
[EX A]:
2