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 two computers on a table'. Find frequency of the letter 'r'

Answer: 2

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

Answer: 3

Question: Sentence: 'a giraffe is standing near some green, leafy trees'. Find frequency of the letter 'a'

Answer:
5