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

[EX Q]: Sentence: 'party cakes in plastic containers, with a cake with a plastic santa claus and reindeer on top'. Find frequency of the letter 's'
[EX A]: 6

[EX Q]: Sentence: 'a toasted sub sandwich is next to a salad'. Find frequency of the letter 'a'
[EX A]: 6

[EX Q]: Sentence: 'a number of boxed foods sitting on a piece of cardboard'. Find frequency of the letter 'o'
[EX A]:
7

