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

[EX Q]: Sentence: 'two giraffes, one standing and one laying down'. Find frequency of the letter 'g'
[EX A]: 3

[EX Q]: Sentence: 'a train going over a bridge with some buildings in the background'. Find frequency of the letter 'd'
[EX A]: 3

[EX Q]: Sentence: 'a man watches a woman behind a counter use a cell phone'. Find frequency of the letter 'c'
[EX A]:
3