instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'a couple of buildings that has a bus out front'. Find frequency of the letter 'a'
answer:
4


question:
Sentence: 'people fishing and enlarge mountainlake with trees lining the shoreline'. Find frequency of the letter 't'
answer:
4


question:
Sentence: 'people sitting on a bench next to a park with someone's rear view mirror in the foreground'. Find frequency of the letter 's'
answer:

3