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: 'a sailboat is floating near the rocky shore of a beach'. Find frequency of the letter 'o'
[A]: 5


[Q]: Sentence: 'a set of long tables with various people siting and standing at the tables, with laptop computers in front of them'. Find frequency of the letter 'i'
[A]:
7