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

[EX Q]: Sentence: 'a surfer wipes out on a huge wave'. Find frequency of the letter 'a'
[EX A]: 3

[EX Q]: Sentence: 'a red train traveling down train tracks near a forest'. Find frequency of the letter 'f'
[EX A]: 1

[EX Q]: Sentence: 'bedroom with large tub and sink in corner'. Find frequency of the letter 't'
[EX A]:
2