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

[Q]: Sentence: 'three men in military suits are sitting on a bench,'. Find frequency of the letter 'a'
[A]: 3


[Q]: Sentence: 'party cakes in plastic containers, with a cake with a plastic santa claus and reindeer on top'. Find frequency of the letter 's'
[A]: 6


[Q]: Sentence: 'a red tour bus riding down a street'. Find frequency of the letter 'd'
[A]:
3