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

[Q]: Sentence: 'a woman cross country skiing in a competition'. Find frequency of the letter 's'
[A]: 3


[Q]: Sentence: 'a tennis player that is running to get the tennis ball'. Find frequency of the letter 't'
[A]: 7


[Q]: Sentence: 'a group of people sitting around a table with plates of food'. Find frequency of the letter 'p'
[A]:
4