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 fluffy white car looking in a mirror'. Find frequency of the letter 'k'

Answer: 1


Question: Sentence: 'two people under an umbrella while walking down a sidewalk'. Find frequency of the letter 'i'

Answer: 3


Question: Sentence: 'two men are playing a tennis game on a court'. Find frequency of the letter 'r'

Answer:
2