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

[EX Q]: Sentence: 'a woman in a messy kitchen with a child'. Find frequency of the letter 'a'
[EX A]: 4

[EX Q]: Sentence: 'a cooked pizza on a silver platter with another in the background'. Find frequency of the letter 'e'
[EX A]: 5

[EX Q]: Sentence: 'man sitting on a train typing on his laptop'. Find frequency of the letter 'o'
[EX A]:
3