instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'a big bear walks through some grass'. Find frequency of the letter 'a'
answer:
4


question:
Sentence: 'a person holding onto a pink kite at the beach'. Find frequency of the letter 'n'
answer:
4


question:
Sentence: 'a boy skating on his skateboard with grafiti in the background'. Find frequency of the letter 'r'
answer:

3