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

[Q]: Sentence: 'a young man with glasses on is taking a big bite'. Find frequency of the letter 's'
[A]: 4


[Q]: Sentence: 'the interior of a living and dining room'. Find frequency of the letter 'i'
[A]: 6


[Q]: Sentence: 'old school refrigerator with clutter atop of it and to the side'. Find frequency of the letter 'l'
[A]:
3