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

[EX Q]: Sentence: 'an elephant has taken a man's hat in its trunk'. Find frequency of the letter 'p'
[EX A]: 1

[EX Q]: Sentence: 'town clocks affixed to a tall, brick building'. Find frequency of the letter 'r'
[EX A]: 1

[EX Q]: Sentence: 'the cat is climbing up in the fridge'. Find frequency of the letter 'e'
[EX A]:
3