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 couple of people are sitting at a table'. Find frequency of the letter 'e'
answer:
5


question:
Sentence: 'a large boat is going down the river'. Find frequency of the letter 'o'
answer:

3