instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'an image of a street sign with a corner restaurant'. Find frequency of the letter 'u'
answer:
1


question:
Sentence: 'a woman at a table checking her cell phone'. Find frequency of the letter 'a'
answer:
5


question:
Sentence: 'people dressed as santa and mrs. claus stand alongside a highway and look at a hill'. Find frequency of the letter 'k'
answer:

1