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

[EX Q]: Sentence: 'a woman is playing an interactive video game'. Find frequency of the letter 't'
[EX A]: 2

[EX Q]: Sentence: 'a person with some scissors over a bowl'. Find frequency of the letter 's'
[EX A]: 6

[EX Q]: Sentence: 'a clear glass vase with some very pretty flowers'. Find frequency of the letter 'a'
[EX A]:
4