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 men standing on the side of a boat'. Find frequency of the letter 'o'

Answer: 5


Question: Sentence: 'a plastic container next to a toilet on a wooden box'. Find frequency of the letter 'i'

Answer: 3


Question: Sentence: 'people waiting for a subway train in a station'. Find frequency of the letter 'a'

Answer:
6