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 family sitting at a table in a restaurant looking at their phones'. Find frequency of the letter 't'
answer:
8


question:
Sentence: 'a person taking pictures at a stadium event'. Find frequency of the letter 'n'
answer:

3