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

[EX Q]: Sentence: 'a mixed bouquet of flowers in a glass vase set before a window'. Find frequency of the letter 'w'
[EX A]: 3

[EX Q]: Sentence: 'a woman and a child walking down a street with a kite'. Find frequency of the letter 'n'
[EX A]: 4

[EX Q]: Sentence: 'a giraffe standing outside doing a silly pose'. Find frequency of the letter 'e'
[EX A]:
3