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

[EX Q]: Sentence: 'a bird in a tree looking up at branches'. Find frequency of the letter 'e'
[EX A]: 3

[EX Q]: Sentence: 'girls posing of a picture one holding a tennis racket the other wearing a crown'. Find frequency of the letter 'g'
[EX A]: 4

[EX Q]: Sentence: 'a bowl of soup, a metal spoon, and an orange on a wood surface'. Find frequency of the letter 'o'
[EX A]:
9