instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'a gray elephant is in a grassy field'. Find frequency of the letter 'e'
answer:
3


question:
Sentence: 'a grey hummingbird by fence and tree branches'. Find frequency of the letter 'y'
answer:
2


question:
Sentence: 'three stuffed animals one has a key around it's neck and one is wearing a red jacket'. Find frequency of the letter 'e'
answer:

10