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

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


[Q]: Sentence: 'small airplane in the process of taking off'. Find frequency of the letter 'e'
[A]: 3


[Q]: Sentence: 'a couple of items that are on the wall'. Find frequency of the letter 'm'
[A]:
1