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

[Q]: Sentence: 'a young boy standing in front of a counter with dougnuts'. Find frequency of the letter 'o'
[A]: 6


[Q]: Sentence: 'two laptop computers sitting on top of a white table'. Find frequency of the letter 'f'
[A]: 1


[Q]: Sentence: 'a plate with french fries and a hot dog and beef sandwich topped with cheese'. Find frequency of the letter 'n'
[A]:
4