instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'a train going over a bridge with some buildings in the background'. Find frequency of the letter 'd'
answer:
3


question:
Sentence: 'person wearing all white leaned up against a wall with a yellow sign'. Find frequency of the letter 'a'
answer:
8


question:
Sentence: 'a glazed yeast doughnut on a paper sheet'. Find frequency of the letter 'o'
answer:

2