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: 'oranges are sitting in a bowl on a table'. Find frequency of the letter 'a'
[EX A]: 5

[EX Q]: Sentence: 'a man playing tennis on a tennis court'. Find frequency of the letter 'm'
[EX A]:
1