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 small dog sits in the rear window of a car'. Find frequency of the letter 'm'

Answer: 1


Question: Sentence: 'a red train traveling down train tracks near a forest'. Find frequency of the letter 'f'

Answer: 1


Question: Sentence: 'an adult and a baby elephant walking through tall dry grass'. Find frequency of the letter 'r'

Answer:
3