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

[Q]: Sentence: 'a bedroom with a neatly made bed and a laptop'. Find frequency of the letter 'l'
[A]: 2


[Q]: Sentence: 'this is a sign in front of a large cathedral'. Find frequency of the letter 'a'
[A]: 5


[Q]: Sentence: 'a man flying through the air while riding a skateboard'. Find frequency of the letter 'd'
[A]:
2