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 train station with a train pulling into the platform'. Find frequency of the letter 'i'

Answer: 6


Question: Sentence: 'a man is taking a picture of a man and woman'. Find frequency of the letter 'a'

Answer: 8


Question: Sentence: 'a woman in a pink coat, is holding an umbrella'. Find frequency of the letter 'i'

Answer:
4