instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'a person does a trick on a ramp on a snowboard'. Find frequency of the letter 's'
answer:
3

question:
Sentence: 'a piece of film shows two street signs crossing each other'. Find frequency of the letter 'f'
answer:
2

question:
Sentence: 'a person holding a napkin and eating a hotdog'. Find frequency of the letter 'd'
answer:
3