instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'there is a baseball game on and a few people are watching'. Find frequency of the letter 'i'
answer:
2


question:
Sentence: 'a flock of sheep grazing in a park'. Find frequency of the letter 'f'
answer:
2


question:
Sentence: 'a woman playing on her cell phone while walking down the street'. Find frequency of the letter 'a'
answer:

4