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 black computer with a screen reading "press any key to begin."'. Find frequency of the letter 'a'

Answer: 5


Question: Sentence: 'a golden haired dog looking out of an open window'. Find frequency of the letter 'd'

Answer: 4


Question: Sentence: 'a bowl of food on plate on a table'. Find frequency of the letter 'l'

Answer:
3