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 picture of a toilet and toilet paper in a bathroom'. Find frequency of the letter 'o'

Answer: 5


Question: Sentence: 'a person on a sidewalk jumping with an umbrella'. Find frequency of the letter 'a'

Answer: 5


Question: Sentence: 'a group of tennis players on a tennis court'. Find frequency of the letter 'o'

Answer:
4