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

[EX Q]: Sentence: 'an old glass vase containing flowers on a glass table'. Find frequency of the letter 'b'
[EX A]: 1

[EX Q]: Sentence: 'a woman is looking at sheep off in a field'. Find frequency of the letter 'm'
[EX A]: 1

[EX Q]: Sentence: 'a man sitting on a couch between two people using laptops'. Find frequency of the letter 's'
[EX A]:
3