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 man and a woman are walking down the street with an umbrella over their heads'. Find frequency of the letter 'w'

Answer: 4

Question: Sentence: 'two men in black wet suits beside a white surfboard'. Find frequency of the letter 'e'

Answer: 5

Question: Sentence: 'a person in a red suit snowboarding down a hill'. Find frequency of the letter 'o'

Answer:
4