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 herd of giraffes in tall african grass'. Find frequency of the letter 'a'

Answer: 6


Question: Sentence: 'a man flying through the air on a bicycle'. Find frequency of the letter 'u'

Answer: 1


Question: Sentence: 'two uniformed people riding horses on a road'. Find frequency of the letter 'd'

Answer:
3