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

[Q]: Sentence: 'a picture of a toilet and toilet paper in a bathroom'. Find frequency of the letter 'o'
[A]: 5


[Q]: Sentence: 'a young boy holding a piece of paper on top of a table'. Find frequency of the letter 'y'
[A]: 2


[Q]: Sentence: 'a man on skis performs a jump in the snow'. Find frequency of the letter 's'
[A]:
4