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

[Q]: Sentence: 'a young woman dressed in green and black operating a remote control'. Find frequency of the letter 'r'
[A]: 5


[Q]: Sentence: 'surfboard being displayed in stor window with clothes behind it'. Find frequency of the letter 't'
[A]: 4


[Q]: Sentence: 'three young children playing with a ball in front of a huge bridge'. Find frequency of the letter 'e'
[A]:
5