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

[EX Q]: Sentence: 'three people are gathered around sitting on a park bench'. Find frequency of the letter 'g'
[EX A]: 2

[EX Q]: Sentence: 'a woman in yellow dress standing next to a horse'. Find frequency of the letter 'l'
[EX A]: 2

[EX Q]: Sentence: 'a dog in a studded collar standing on the seat of a motorcycle'. Find frequency of the letter 'e'
[EX A]:
4