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

[EX Q]: Sentence: 'a man hitting a tennis ball with a tennis racquet'. Find frequency of the letter 't'
[EX A]: 6

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

[EX Q]: Sentence: 'a dog hiding in the cushion of a couch by a blanket'. Find frequency of the letter 't'
[EX A]:
2