instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'a street at night with trees and streetlights on'. Find frequency of the letter 't'
answer:
9


question:
Sentence: 'a blue fire hydrant painted on the bottom of it'. Find frequency of the letter 'h'
answer:
2


question:
Sentence: 'a herd of zebra standing on top of a dry grass field'. Find frequency of the letter 'o'
answer:

4