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 girl that has a kite in the air'. Find frequency of the letter 'r'

Answer: 2


Question: Sentence: 'a surfer wipes out on a huge wave'. Find frequency of the letter 'a'

Answer: 3


Question: Sentence: 'a line of bicycles beside a street where a bus is stopping for passengers'. Find frequency of the letter 'n'

Answer:
3