instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'a police officer who is riding on a horse'. Find frequency of the letter 'p'
answer:
1


question:
Sentence: 'a man in a black wet suit rides an orange surfboard on the water'. Find frequency of the letter 'o'
answer:
3


question:
Sentence: 'a man spins a frisbee on his finger'. Find frequency of the letter 'i'
answer:

4