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 small white dog looking out a car window'. Find frequency of the letter 'l'

Answer: 3


Question: Sentence: 'a person riding a skate board on a city street'. Find frequency of the letter 'a'

Answer: 5


Question: Sentence: 'the woman is dressed in makeup riding her skateboard'. Find frequency of the letter 'e'

Answer:
6