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 toasted sub sandwich is next to a salad'. Find frequency of the letter 'a'

Answer: 6


Question: Sentence: 'a close up of a bird on the outside window sill'. Find frequency of the letter 'c'

Answer: 1


Question: Sentence: 'officers are standing and on horses to form a line across a town center'. Find frequency of the letter 's'

Answer:
6