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

[Q]: Sentence: 'group of cars on the road with the sun setting behind it'. Find frequency of the letter 'd'
[A]: 2


[Q]: Sentence: 'a golden haired dog looking out of an open window'. Find frequency of the letter 'd'
[A]: 4


[Q]: Sentence: 'several young people sitting at a table eating cookies'. Find frequency of the letter 'i'
[A]:
4