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

[EX Q]: Sentence: 'a street scene looking at the back of the stop sign'. Find frequency of the letter 't'
[EX A]: 6

[EX Q]: Sentence: 'a black horse with a white dot on its forehead'. Find frequency of the letter 't'
[EX A]: 4

[EX Q]: Sentence: 'a man holding holding a tennis racquet on a tennis court'. Find frequency of the letter 't'
[EX A]:
4