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: 'a young man riding a skateboard near a forest'. Find frequency of the letter 'd'
answer:
2


question:
Sentence: 'a group of giraffes walk together by a hill'. Find frequency of the letter 'b'
answer:

1