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

[EX Q]: Sentence: 'a green bus driving in a street filled with heavy traffic'. Find frequency of the letter 'v'
[EX A]: 2

[EX Q]: Sentence: 'the child is waving a small flag as she stands near two women'. Find frequency of the letter 'g'
[EX A]: 2

[EX Q]: Sentence: 'a kitchen containing an oven, a microwave and a kitchen island'. Find frequency of the letter 'w'
[EX A]:
1