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 bed with a mattress that has nothing on it'. Find frequency of the letter 'a'

Answer: 5


Question: Sentence: 'a man in a sweatshirt is taking his own picture'. Find frequency of the letter 'u'

Answer: 1


Question: Sentence: 'a train pulling into a train station next to a housing structure'. Find frequency of the letter 'h'

Answer:
1