instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'a man standing on a surf board in the ocean'. Find frequency of the letter 'f'
answer:
1


question:
Sentence: 'two elephants walking on cement next to wall'. Find frequency of the letter 'n'
answer:
5


question:
Sentence: 'three zebras that are standing in the grass'. Find frequency of the letter 'd'
answer:

1