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 couple of buses parked on the side of the street'. Find frequency of the letter 'b'

Answer: 1


Question: Sentence: 'the large modern train is on the train track'. Find frequency of the letter 'm'

Answer: 1


Question: Sentence: 'a red, black and yellow train coming down the tracks by a body of water'. Find frequency of the letter 'o'

Answer:
5