instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'a player swings his bat at a baseball game'. Find frequency of the letter 'p'
answer:
1


question:
Sentence: 'a gray elephant is in a grassy field'. Find frequency of the letter 'e'
answer:
3


question:
Sentence: 'a tall building with antenna stands before a jet flying in the background'. Find frequency of the letter 't'
answer:

6