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: 'many white birds flying above a river that flows in front of a forest'. Find frequency of the letter 'a'

Answer: 5


Question: Sentence: 'two metal  benches on an empty train platform'. Find frequency of the letter 'n'

Answer: 4


Question: Sentence: 'three ties, a watch and a book on a table'. Find frequency of the letter 'e'

Answer:
4