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

[EX Q]: Sentence: 'man in red shirt with black suitcase standing outside of building'. Find frequency of the letter 'i'
[EX A]: 8

[EX Q]: Sentence: 'a big bear walks through some grass'. Find frequency of the letter 'a'
[EX A]: 4

[EX Q]: Sentence: 'side view of two standing elephants with a man on neck of one, both elephants with trunks to ground, in front of two long logs outside with hut and trees behind'. Find frequency of the letter 'i'
[EX A]:
9