In this task, you need to count the number of times the given letter appears in the given sentence.
--------
Question: Sentence: 'a man holding a baseball bat an playing baseball'. Find frequency of the letter 'l'

Answer: 6


Question: Sentence: 'two men sitting quietly on a park bench'. Find frequency of the letter 'a'

Answer: 2


Question: Sentence: 'an adult giraffe sits down while a baby giraffe investigates'. Find frequency of the letter 'g'

Answer:
3