In this task, you need to count the number of times the given letter appears in the given sentence.
--------
Question: Sentence: 'a person riding a surfboard in the middle of a wave'. Find frequency of the letter 'o'

Answer: 3


Question: Sentence: 'man in red shirt with black suitcase standing outside of building'. Find frequency of the letter 'i'

Answer: 8


Question: Sentence: 'a young child resting his leg on a bench'. Find frequency of the letter 'g'

Answer:
3