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

[Q]: Sentence: 'a man skating down a stair rail in front of a bunch of people'. Find frequency of the letter 'o'
[A]: 5


[Q]: Sentence: 'four men standing around two pizzas in a conference room'. Find frequency of the letter 't'
[A]: 2


[Q]: Sentence: 'two women holding something together smiling at each other'. Find frequency of the letter 'n'
[A]:
4