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: 'vanity sitting atop a base with two doors and a mirror overhead'. Find frequency of the letter 'n'

Answer: 3


Question: Sentence: 'a red fire hydrant opened and spilling water'. Find frequency of the letter 'd'

Answer: 4


Question: Sentence: 'the three clear vases each have flowers in them'. Find frequency of the letter 'a'

Answer:
4