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

[EX Q]: Sentence: 'a toilet sits in a cluttered bathroom next to a sink'. Find frequency of the letter 'a'
[EX A]: 4

[EX Q]: Sentence: 'a man in costume talking on a cell phone'. Find frequency of the letter 'm'
[EX A]: 2

[EX Q]: Sentence: 'there is a click tower on the front of the building'. Find frequency of the letter 'i'
[EX A]:
4