instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'a sheep in a field in front of other sheep'. Find frequency of the letter 'f'
answer:
3

question:
Sentence: 'a man skating down a stair rail in front of a bunch of people'. Find frequency of the letter 'o'
answer:
5

question:
Sentence: 'a guy jumping high into the air on his skate board'. Find frequency of the letter 's'
answer:
2