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

[Q]: Sentence: 'a cat sprawls out and sleeps on its back on a lounge chair with an acorn theme'. Find frequency of the letter 'r'
[A]: 3


[Q]: Sentence: 'a person is water skiing and there are birds flying around above them'. Find frequency of the letter 'n'
[A]: 5


[Q]: Sentence: 'several people are flying kites in an open field'. Find frequency of the letter 'p'
[A]:
3