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

[EX Q]: Sentence: 'a woman with short, brown hair is looking into a circular mirror and holding a camera up to her cheek'. Find frequency of the letter 'e'
[EX A]: 4

[EX Q]: Sentence: 'an empty clean kitchen with island, marble countertops , stove and cabinetry'. Find frequency of the letter 'l'
[EX A]: 3

[EX Q]: Sentence: 'a large herd of zebras stand in a grassy field'. Find frequency of the letter 'r'
[EX A]:
4