instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'a crowd of people standing in front of a green train'. Find frequency of the letter 'g'
answer:
2


question:
Sentence: 'a man with glasses adjusting his tie in a mirror'. Find frequency of the letter 's'
answer:
5


question:
Sentence: 'a gray colored pigeon that is perched on a railing outside of a building, with other buildings in the background'. Find frequency of the letter 'e'
answer:

7