instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'three young people goofing around; one of the guys has a football, the girl has a teddy bear'. Find frequency of the letter 'd'
answer:
3


question:
Sentence: 'a man in a black shirt prepares to catch a frisbee'. Find frequency of the letter 'f'
answer:
1


question:
Sentence: 'an asian woman talking on her cell phone'. Find frequency of the letter 'n'
answer:

6