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

[Q]: Sentence: 'a man sitting inside a green military truck talking to someone'. Find frequency of the letter 'i'
[A]: 7


[Q]: Sentence: 'a close up of a plate with a whole carrot'. Find frequency of the letter 'w'
[A]: 2


[Q]: Sentence: 'a blurry photograph of a family with tennis gear crossing a city street'. Find frequency of the letter 'o'
[A]:
4