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

[Q]: Sentence: 'a girl hitting a tennis ball on a court'. Find frequency of the letter 'l'
[A]: 3


[Q]: Sentence: 'a stuffed animal sitting on an empty bed'. Find frequency of the letter 'u'
[A]: 1


[Q]: Sentence: 'a kitchen that is clean and ready for someone to cook in'. Find frequency of the letter 'e'
[A]:
5