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: 'an old woman is holding her cat in front of a camera'. Find frequency of the letter 'r'

Answer: 3


Question: Sentence: 'a black horse with a white dot on its forehead'. Find frequency of the letter 't'

Answer: 4


Question: Sentence: 'the large modern train is on the train track'. Find frequency of the letter 'm'

Answer:
1