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

[Q]: Sentence: 'a toilet of some sort near a sink of some sort'. Find frequency of the letter 'o'
[A]: 7


[Q]: Sentence: 'a person is performing a stunt on a snowboard'. Find frequency of the letter 'p'
[A]: 2


[Q]: Sentence: 'a plate has beans, mushrooms, broccoli, and carrots on it'. Find frequency of the letter 'r'
[A]:
4