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

[Q]: Sentence: 'a woman throwing a frisbee on a field'. Find frequency of the letter 's'
[A]: 1


[Q]: Sentence: 'children with scissors and construction paper in a school classroom'. Find frequency of the letter 'c'
[A]: 6


[Q]: Sentence: 'a very odd looking wagon by a big two level bus'. Find frequency of the letter 'e'
[A]:
3