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 boat and a large boat on a river near a city'. Find frequency of the letter 'a'

Answer: 10


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

Answer: 8


Question: Sentence: 'large white and blue air plane taking off'. Find frequency of the letter 'i'

Answer:
3