instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'people waiting on a train platform in a wooded area'. Find frequency of the letter 'p'
answer:
3


question:
Sentence: 'a man opening up a package sitting on a couch'. Find frequency of the letter 'n'
answer:
5


question:
Sentence: 'a stuffed bear on top of garbage on the street'. Find frequency of the letter 'n'
answer:

2