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

[EX Q]: Sentence: 'a man flying through the air on top of a skateboard'. Find frequency of the letter 'r'
[EX A]: 3

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

[EX Q]: Sentence: 'a pizza pie sitting on a wooden table with tongs'. Find frequency of the letter 't'
[EX A]:
5