instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'some sheep are standing in a grassy field'. Find frequency of the letter 'n'
answer:
3

question:
Sentence: 'a photo of a toilet which is not clean'. Find frequency of the letter 'w'
answer:
1

question:
Sentence: 'a tennis player with a racket and a ball'. Find frequency of the letter 'i'
answer:
2