instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'three young children playing with a ball in front of a huge bridge'. Find frequency of the letter 'e'
answer:
5


question:
Sentence: 'statues of 2 zebras and 1 giraffe in a doorway'. Find frequency of the letter 'a'
answer:
6


question:
Sentence: 'a city at night with a green traffic signal'. Find frequency of the letter 'f'
answer:

2