instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'a man riding a white surfboard on a large wave'. Find frequency of the letter 'a'
answer:
7


question:
Sentence: 'a group of cows that are standing in the grass'. Find frequency of the letter 'g'
answer:
3


question:
Sentence: 'a young person on a parked motorcycle next to a person in costume'. Find frequency of the letter 'o'
answer:

8