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

[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 couple of items that are on the wall'. Find frequency of the letter 'm'
[EX A]: 1

[EX Q]: Sentence: 'the flowers are in a vase on the table'. Find frequency of the letter 'l'
[EX A]:
2