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 man on a skateboard going down a ramp while people are watching'. Find frequency of the letter 'w'

Answer: 3

Question: Sentence: 'a small boat and a large boat on a river near a city'. Find frequency of the letter 'a'

Answer: 10

Question: Sentence: 'a gas range with a microwave oven mounted overhead'. Find frequency of the letter 'm'

Answer:
2