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

[EX Q]: Sentence: 'a man swinging a bat while playing baseball'. Find frequency of the letter 'm'
[EX A]: 1

[EX Q]: Sentence: 'a young boy wearing black and holding a skateboard on the sidewalk'. Find frequency of the letter 'n'
[EX A]: 5

[EX Q]: Sentence: 'a cooked pizza has pepperonis among other ingredients'. Find frequency of the letter 'k'
[EX A]:
1