In this task, you need to count the number of times the given letter appears in the given sentence.
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Question: Sentence: 'a group of people having dinner and drinking wine'. Find frequency of the letter 'r'

Answer: 3


Question: Sentence: 'a cat that is standing next to an open suitcase'. Find frequency of the letter 'e'

Answer: 3


Question: Sentence: 'a group of snowboarders coming down a slope'. Find frequency of the letter 's'

Answer:
3